Open Source Flash Projects

Open Source Flash Projects

Flash IDE Alternatives

AjaxAnimator - An online, collaborative, web-based animation suite with support for exporting to Flash, Silverlight, GIFs, and more Homepage Live Application - “Last release - Wed Feb 17 2010” - Ray James

ForkSwif - A desktop flash IDE coded in C# based off of SVGPaint and uses swfmill for svg generation. ForkSwif Project Homepage - “This project no longer seems to be alive and the links are dead.” 08/21/2011 - Ray James
Open Dialect - A Flex based Flash IDE for creating and publishing Flash Movies check out the Open Dialect Home Page

Salasaga - In development eLearning IDE, aiming to be an improvement on Adobe's Captivate. Salasaga Homepage

SWIFT -SWIFT (which stands for “ShockWave Is Free Territory”) is a free, open-source alternative to Adobe Flash. It is written in Python, and uses PyGTK for a GUI, swfc for compiling, and Cairo for image processing. Development on SWIFT has stopped to focus on Lightningbeam. SWIFT

Lightningbeam - Lightningbeam is a rewrite of SWIFT from the ground up, focusing on consistency and portability. Lightningbeam is written in Python and uses PyGUI for a windowing system, allowing it to run on Linux, Windows and Mac OSX. Lightningbeam Blog

Command Line Tools, Compilers, etc.

AFLAX - JavaScript development library for Flash. No ActionScript or compiler required.
AS Class Exporter - A .NET utility that extracts the names of the classes compiled in a set of swf's, searches a defined classpath to find the referenced classes and copies the .as files found in said classpath to an output folder chosen by the user. Home page on Google Code
AS3Commons - ActionScript3 port of java.utils and container classes
AS3Converter - An Ant task and some scripts to aid porting ActionScript2 projects to ActionScript3.
ASFoundry - An ActionScript 3 / Java framework designed for Flex 2 applications development
C Preprocessor for ActionScript - A GNU Make and Microsoft NMake script and tools to seamlessly hack the C processor into Flex SDK mxmlc builds or Flash 8/CS3 builds. Works well in various IDEs, including jEdit and Developer Studio. Also provides simple code obfuscation to reduce the rewards for decompiling.
EnLarge - ActionScript preprocessing tool that enables the development of a single code base that targets Flash Player (7, 8 and 9), Flash Lite 2 and GNU Gnash.
FAR - FlashArchive, a command line tool for creating ZLIB compressed archives that can be streamed in progressively from the Flash player at run-time, using the provided ActionScript 3 API.
FFMPEG - Video transcode engine which also supports the flv
FlashCommand - a command line compiler for Flash IDE. Developed by Mike Chambers of Adobe.
Flasm - Assembler/Disassembler for ActionScript Bytecode
FleVI - Flex 2.0.1 SDK Visual tool for easy development of Flex / AS 3.0 projects for Flashplayer 9.Supports auto project creation, Application + Component compiler & ASDoc.
Flexcover - Code coverage collection and reporting tools for AS3. Based on modified open-source MXMLC compiler from Flex SDK.
FLVTool2 - FLV Metadata Updater
FreeMovie A pure PHP framework for creation of flash.
haXe, a new language that targets Flash Player 6 to 9, but also Javascript/AJAX and Server-side development
itface - Console AS3 compiler using FlexBuilder alpha.
JavaSWF2 - JavaSWF2 is a set of Java packages that enable the parsing, manipulation and generation of the Macromedia Flash(TM) file format known as SWF (“swiff”).
JGenerator - The JGenerator is the web server production application that can dynamically combine text, graphics, and sound to build rich Flash content, and is a free alternative to Macromedia Generator.
JSwiff - pure Java framework for Macromedia Flash file creation and manipulation.
Kagswf - simple to use SWF builder, a tool made of Mtasc and Swfmill with various improvements (library of basic visual components, automatic generation of HTML code etc.)
Ming - Ming is a C library for generating SWF (“Flash”) format movies, plus a set of wrappers for using the library from C++ and popular scripting languages like PHP, Perl, Python, and Ruby.
MTASC - ActionScript Compiler
Pair - Pair is Python for AIR, allowing you to create standalone desktop applications with bundled AIR and Python runtimes.
RABCDAsm - ActionScript 3 Bytecode Assembler/Disassembler
RSWF - Rebol script for making and exploring SWF files
s2x - Python script for converting .sol to XML and back.
ScreenweaverHX, enables you to access OS/Desktop functionalities from Flash and build Rich Desktop Applications.
Sprouts - Takes the tedium and frustration out of creating new programming projects by automatically copying easily-modified project templates, then installing and configuring all required external tools, libraries and build tasks.
swcextract - Extract, consolidate, rename and organize intrinsic ActionScript class files and (optionally) component SWFs from SWC files.
SWF Tools - SWF Tools is a collection of SWF manipulation and creation utilities written by Rainer Böhme and Matthias Kramm. It is released under the GPL.
Swfmill - XML to SWF, SWF to XML command line compiler
Torta - Torta generates a flash file that shows you how your disk space is being used. Torta is written in Common Lisp.
Transform SWF - Java library that enables you to parse and create SWF files (Flash 10 fully supported)
vixy.net flv2mpeg4 - FLV to AVI/MP4/MOV command line transcoder
xml2swf - C program that converts xml to swf. Builds on Linux/Posix or Windows (using mingw and msys) systems.
HippoHX - HippoHX is a tool for building Flash desktop applications. It's based on ScreenweaverHX and aims to be an Open Source counter part of Adobe AIR or Zinc.
flvlib - Python FLV library that can also inject onMetadata tags

Eclipse, Flash IDE and Plug-ins

Eclipse - The IDE platform

Ant - Used by Eclipse to automate the building of Flash projects
As2 Class Browser - plugin - Accessible through the Eclipse Help Panel
asdt - ActionScript Development Tool
Colorer-take5 - A syntax-highlighting Eclipse plugin that supports Actionscript
Flair - A Set of plugins for log and view SWF
IDE for Laszlo - Wysiwyg editor plugin/IDE for Laszlo
J2AS - Java to ActionScript Converter
LiveDocs Browser - Browse MM's LiveDocs through the Eclipse Help Panel

flasc - FlashIDE + MTASC Compiler = FLASC | Flash IDE plugin for compiling with MTASC

Editors

FlashDevelop - a popular open source ActionScript 2/3 and web development environment. FlashDevelop seamlessly integrates with Adobe Flash IDE, Adobe Flex SDK, Mtasc, Haxe and Swfmill.
jEdit - A cross-platform programmer's editor written in Java and enhanced for ActionScript development through plugins and macros.
Sepy - A full featured ActionScript editor written in python and wxPython.
MiniBuilder - Online AS3 IDE, edit (with code assist) and compile SWF. Runs in the browser. author's blog.

ActionScript

actionstep - Open source component framework project based on NextStep/OpenStep/GNUStep/Cocoa “Application Kit”
AnimationPackage - helps you to create powerful and maintainable animations in an efficient and easy way.
ActionScript Facile - Open source component framework AS3 Facile : une « Bibliothèque Flash de Composants Graphiques développée en AS3 » (Button, Scrollbar, Tooltip, List, ComboBox…).
arp - Pattern-based RIA framework (ActionScript 2) for Flash and Flex.
AS DataProvider Controls library - Set of lightweight standard user interface components. Including ListView, TreeView, SelectBox, Button, ScrollPane, ColorPicker, …
AS Layout Engine -The AS Layout Engine is written in AS 3 and provides containers such as Stack Panel and Wrap Panel to ease the development of the Presentation layer.
As2lib - Open source framework (ActionScript 2) that offers support for event handling, error handling, logging, overloading, reflections, data holders, iterators, unit testing, mock objects, profiling, local connections and file loading (is Flash, Flex, MTASC, FAME, … compatible)
AS3Commons Collections Framework - The most serious ActionScript collections resource in the web – providing both a sophisticated collections framework as well as a library of fast collection implementations.
AS3Commons UI - Algorithms and managers to serve common UI releated tasks such as layouting, focus and keyboard management, popup handling, drag and drop control and so on. All packages support native Flash display objects. Usage of UI does not require interface implementations. The first version (0.1.x) includes the sole layout package.
AS3 Crypto Library - Cryptography library for as3, featuring RSA, AES, 3DES, BlowFish, RC4, MD5, SHA-1, SHA-256 and more. BSD license.
as3matrix - A powerful Matrix library for Actionscript 3.0
as3cannonball - DOM+HTML+CSS+Window Library for ActionScript 3.0. Cannonball is an implementation of the DOM Level 3 and CSS3 core specifications.
as3htmltidylib - Alchemy build of HTMLTidy for client-side HTML cleanup in Flash/Flex projects.
AS3 Mixins - Mixins library for Actionscript 3.
as3mathlib - Numerical Routines library for Actionscript 3, including Geometry, Integration, Differentiation, Complex, Polynomial and Symbolic calculations.
as3midilib - Library for decoding and working with MIDI devices and files in Flash.
as3scriptinglib - ECMAScript/AS3/JavaScript engine for ActionScript 3.0. This is an API for incorporating the ECMAScript compiler (from the Tamarin project) into your Flash or Flex app.
AS3 Signals - a new approach for AS3 events, inspired by C# events and signals/slots in Qt. Started by Robert Penner.
ASAP Framework - A Flash ActionScript 2.0 RIA library for the development of maintainable, multi-movie, event based interactive applications. Compatible with both MTASC and MMC.
ASCrypt - Cryptography classes for Actionscript 2
AsGeolocation - Designed to help Flex developers use the new geolocation features availible in Firefox 3.5 and Chrome with Gears.
ASIoC - Simple Inversion of Control for ActionScript
ASLib - An ActionScript 2.0 based library that implements common data structures.
ASTUce - An ECMAScript regression framework based on JUnit
AsUnit - Unit testing framework for ActionScript 2 and 3 (works with Flash, Flex, MTASC, MXMLC, FAME, etc.)
AsWing - AsWing is an ActionScript Component Framework based on Java Swing.
AS-HIVE - A state-based MVC framework for AS3.
Away3d - Advanced realtime 3d engine.
BBC OSFlash - List of open source Flash projects from the BBC
BetterFLV - Alternative to Adobe's stock FLVPlayback Component
BiG - AS2 | FlashRemoting Image Gallery.
BitmapDataUnlimited - A wrapper class to generate BitmapData objects greater than 2880 pixel (AS3)
Cairngorm - Pattern-based RIA framework (ActionScript 2 and 3) for Flex and Flash.
CASA Lib - CASA Lib is a flexible ActionScript library designed to streamline common chores and act as a solid, reliable foundation for your projects. It provides a core set of classes, interfaces, and utilities to get you coding faster and more reliably without getting in the way.
CleVR Actionscript Library - Matrix algebra and image manipulation library, originally produced for the CleVR.com photo stitcher.
Open Source FLV player - An open source, embeddable flv player.
Component Security Manager - UI security and management for Flex / AIR applications.
core2 - An ECMAScript library that extend the core objects.
deface - AS3 based face/object detection.
disccollision - An open source collision detection system for Flash ActionScript3 (AS3).
DENG - DENG is a Flash 6 component written in ActionScript 1 that renders subsets of XHTML, XForms, SVG, XFrames with CSS
Desuade Motion Package - A lightweight tweening, physics, and sequencing library for AS3
Desuade Partigen - A powerful and lightweight flash particle effects library for AS3
Edumatic - Actionscript 3 e-learning framework similar to ARP
EnFlash - ActionScript Application Framework
ExactText - ActionScript 3. Forget about flash's ability for accurate metrics on textFields. ExactText is accurate to the pixel.
f_TEA - 128-bit encryption system for Flash and PHP.
Fingers - Extremely easy AS3 plug-in. Simplifies event management: on(btn).click += yourListener;. Compatible with your project. Inspired on C# events.
fla2xleff - a .fla to XLEFF converter (part of XLEFF TBX)
Flade3D - A lightweight 3D actionscript physics engine.
Flade - A free library for simulating 2D physics in Flash.
Flash Camouflage - Flash Camo (for short) is a graphics framework that allows AS 3 applications to be easily skinned from pngs, jpgs, or gifs and styled with CSS.
flare - An AS3 toolkit for advanced data visualization and animation.
Flash JavaScript Integration Kit - Allows you to call JavaScript functions from ActionScript, and vice versa. All major data types can be passed between the two environments, and it works across browsers and platforms.
FlashAnt - FlashAnt includes an Apache Ant task for integrating Flash into the build process of Rich Internet Applications.
FlashML - AS2 built HTML renderer and RAD development framework.
Flashr - AS2 wrapper for the flickr.com API.
FlexUnit - Unit testing framework for ActionScript 2 and 3 (Flex and Flash)

flex-spreadsheet - Flex component for grid based data input
Flint particles - Actionscript 3 particle system library for 2D and 3D particle effects in Flash and Flex.
fosFORO - A Text Formatter that allow you to use emoticons and some other tags.
FoxR - ActionScript 3 Frameowrk based on AS3 port of PureMVC. Provides components, integrated CSS stylesheets support, pre-defined visual architecture, utilities and a rich data adapter model for fast track Flash development.
FP XHTML Render - XHTML parser and render component for Macromedia Flash 2004 (ActionScript 2.0).
FUnit Testing Framework - The next generation of metadata-driven unit testing framework for Flex with a friendly and approachable NUnit-style markup.
Fuse - Animation packaged which builds on the functionality of MovieClip Tweening Prototypes
gamepackage - Open source ActionScript 2 framework for gamedevelopment(mode7, raycasting, tile2d, pathfinder,…), an audiopackage and lots of useful util and math classes
GameScroll - Open source ActionScript 2 System|Framework for scroll-gamedevelopment
GUGGAFF - Pattern-based RIA framework for Flash (ActionScript 2)
guttershark - An Actionscript 3 Library targeted for Flash. That provides 95% of the common features needed for any flash website.
Helium - An Actionscript 3 Library for creating custom Adobe AIR installers.
J2AS3 - An Actionscript 3.0 based AS3 to Java converter
Jakute Styling Engine - CSS styling framework for Flash. Supports independent components, external style sheets, global and inline styles, contextual selectors, states, runtime modifications
JumpShip - An MVC ActionScript 3.0 Framework with a Ruby on Rails design philosophy for Flash and Flex.
JSON - JSON (JavaScript Object Notation) is a lightweight data-interchange format, with an open source ActionScript implementation.
Layout Managers - Open source Flash Layout Managers. Complete examples and documentation. FlowLayout, GridLayout, AnimatedFlowLayout, AnimatedGridLayout.
LaTeX2Flash - Open source math typesetting in Flash IDE and dynamically with AS3. Relies on server side LaTeX rendering.
Masapi - Management of massive loading (massload) and file dependencies.
MC Tween - Actionscript tweening extension, used to start transitions and tweens via code on MovieClip, TextField and Sound objects, for both AS1 and AS2. Uses Robert Penner's easing equations.
ModestMaps - A BSD-licensed AS2/AS3/WPF display and interaction library for tile-based maps.
mojocolors - Actionscript 3 color library for working with colors, color harmony, shades, gradients and more.
Movieclip Tweening Prototypes - ActionScript 2 (and 1) api for tweening with lots of easing equations.
MovieClipLoader6 - Flash player 6 compatible implementation of Flash player 7's MovieClipLoader class.
objecthandles - User resizing and movement of controls in Flex applications.
openclasslibrary - An OSFlash hosted collection of Actionscript classes.
Object Oriented ActionScript (OOAS) - A collection of ActionScript 2 and 3 classes to simplify the creation of object based flash programs. Examples include a generic iterator class, unique random item generation, media abstraction classes.
Papervision3d Flash is getting 3D.
Parsley AS3 Application Framework (combining IOC Container and MVC Framework) for Flex/Flash/AIR
pixLib - Framework designed to support event handling, logging, data preloading, managing sound and video, making transitions, data holders and data structures, patterns implementations …
Prana - An Inversion of Control container for AS3 based on Spring. Also contains a Reflection API, several utilities and support for configuring Cairngorm and PureMVC applications.
Pulse Particle System - A particle system for Flash development.
PBGUI - A Minimal Components GUI for Pixel Bender shaders.
Razor Component Framework - A code-only component framework for Actionscript 2 and 3.
Sandy - Complete and powerful Flash 3D engine (AS2&AS3)
Scale9_Plus - ActionScript 2. What is the point of scale9 if it is only good for vector drawings? Apply Scale9 to Bitmaps as well.
SCUGE Skin-able Configurable Universal Gaming Engine - A Framework for writing Flash Games.
sfug library - AS2 and AS3 library done by the Swiss Flash User Group to simplify everyday tasks like animations, data loading, flv playing etc
ScrollAPI - A little framework for quick ScrollBar development
SMX components set - A component library for Flash MX 2004, built with the MX v2 architecture
BaseUI - AS3 layout manager
SomaUI - AS3 Flash MVC Framework (automated)
SpiceLib AS3 Library: Reflection API, Logging, Task Framework.
stk-in-as3 - ActionScript port of The Synthesis ToolKit in C++ (STK). It provides classes for audio signal processing and algorithmic synthesis.
SWFSEO - A Search Engine Friendly Flash Framework. With deeplinking via SWFAddress, powerful preloading, page tracking, and browser scrollbars.
TextHighlighter - highlight Text with custom styles (AS3)
TreeMap - Custom treemap visualization component for Flex 2.
Tweener - A class to create simple or complex tweenings/transitions easily, for both AS2 and AS3.
UltraLoader - A lightweight preloading library that was spawned during the development of the SWFSEO Framework.
Vanilla - Automatic extraction of untyped objects via reflection.
we3d - AS2/AS3 3D Engine
wisASLibrary - An ActionScript 2 library with lots of animation math.
Wrapper - An ActionScript 3 HTML/CSS rendering engine.
XIFF - API for the XMPP Instant Messaging protocol
XLEFF - a XML Layout Engine for Flash
XLEFF TBX - a collection of XLEFF tools (fla2xleff, xleff2as, xleff4mtasc)
xleff2as - creates AS2 code from XLEFF documents
xleff4mtasc - a mtasc compatible version of XLEFF
XPath4AS2 - An XPath library for ActionScript from XFactorStudio.
embetter - Component / attach / detach based Flash development.
VASGen - A build of Violet UML that can export UML Class Diagrams to ActionScript3 code
AsPngEncoder - An AS3 png encoder library support 32-bit, 24-bit truecolor and 8-bit indexed color encoding.
Half-Baked Ray Caster - A 3D ray caster engine for AS3 that uses native 'MovieClip' types for the sprites, rather than chopped up bitmaps. Makes for prettier scaling and more compact animation.
F3Player -The F3 Player have all the mp3 player features.. explored cryptography for registering the flash file like a software
Reflex Unit - A JUnit-style unit testing framework for ActionScript 3 (Flex 2 & Flex 3); includes an Eclipse plug-in for running tests and jumping to failed methods
MIoC - MIoC is a Lightweight metadata-driven IoC application framework for ActionScript 3. MIoC utilizes the reflection capabilities of AVM2 and AS3 to auto-wire classes thus improving code readability and generally aiding the development process.
Svetka - Svetka is eval for ActionScript 3. It uses browser’s Javascript.
splinklibrary - an as3 toolkit featuring event distribution, queues, reflection, logging (log4j style), tweening (queue based) and loading (queue based)
splinkresource - an as3 multilanguage resource loading framework
deepsplink - a lightweight actionscript 3 application framework providing easy to use out of the box deeplink support.
BascKit - Extensible, loosely-coupled application framework that implements useful, common functionality needed for working with events, tasks, RPC, UI, asset loading, skinning, data modeling, and memory-safe data structures. Made to be non-intrusive and to play nice with other frameworks. It has a proven track record on many projects over many years.
miniui - miniui is a ActionScript3?.0 ui framework. It is concise, powerful. It can be custom skin and layout.
Bookmarks - Bookmarks is a simple deep linking framework for Adobe Flex 4. It presents a very simple and flexible approach to handle applications with complex visual hierarchy including web browser management.
as3proj - Port of PROJ.4 map projections.

Browser Add-ons

SWFAddress - Deep linking for Flash and Ajax.
SWFFix - Flash content embed method.
SWFObject - A small Javascript file used for embedding Adobe Flash content.
SWFSound - Small Javascript file for adding cross-browser sound support in DHTML/JavaScript, based on Flash.
SWFResize - A small JavaScript to assist with full-screen Flash applications.
PNGPong - Cross-browser solution for displaying transparent PNGs in IE, Firefox, and Safari using Flash, Javascript, and DHTML.
Osmosis - AS3 support for some browser HTML5 APIs.

Flash Applications

Kaltura - Open source video platform for online video management, creation, interaction and collaboration.
Flaxus - Flaxus is a software developed under the TOPLAP manifesto, to perform visual performances in real time.
FlashMyAdmin - MySQL Administrator application in Flash.
Xical - A Flash/ActionScript based Open Source Rich Media Framework with a player for presentations and e-learning lektures.
Big - A Xhtml/Flash Image gallery
FCMS - a Flash presenter system for phpwcms to allow an HTML and a Flash presentation of the same site data. Uses amfphp(currently pre-alpha)
Open Yaargh!PG - a Online Flash RPG about pirates. Uses amfphp
PROFGallery - PROFGallery is extra customizable flash gallery, with interesting Effect Engine. PROFGallery fits better for extension development for CMS.
FTF Flash Text Formatter - Formats the text according to keyword definition list stored in external XML file.
flashtextarea Flash Text Area - WYSIWYG text area replacement for html forms.
ComCenter ComCenter - ComCenter is a Flex-based image management program.
Flivpee - a Flash video player with javascript widgets and styling through CSS.
open flash chart - Graphs and bar charts. Easy to use and look nice.
Movie Masher - an AS3-based online video editor made to be skinned and extended with custom effects, transitions and controls. Works with any CGI scripting language.
silex - RIA developement tool
Super Alerts - The first and only open flash desktop alert platform.
Javaflash - Javaflash enables Flash runs as SWT widget in Java.
SilentSleeper OS - SilentSleeper OS is free web OS run on User native Desktop to provide free media streaming for the world.
Wonder - A new generation desktop system based on Flash and Java technology.
F3Player -The F3 Player have all the mp3 player features.. explored cryptography for registering the flash file like a software
flashDance CMS - An open source and free Content Management System for flash projects.
Xuroq Flash - An open source website dedicated to providing free flash samples and demos.
1 Flash Gallery - Stylish flash photo gallery and slideshows. Available SWF objects/XML gallery and AS3 components.

Servers and Remoting

Java

Red5 - Open Source Flash RTMP Server
Erlyvideo — Open Source Flash RTMP Server in Erlang
Spark - Java Flash server which supports Remoting and server side JavaScript.
Cinnamon Remoting - AS3 to Java EE Remoting based on AMF3
OpenAMF - Flash Remoting for J2EE
Oregano - A Multiuser Server written in Java
Pimento Data Services - Integrates JPA/Hibernate with Flex/Flash/AIR clients
Jive Messenger - An XMPP Server written in Java which integrates well with the XIFF library.
JOnAS - A J2EE Open Source Application Server. This server is Sun Certified since v4.3.4.
Firewater Framework - REST based web APIs for your Java and Flash/Flex applications.
flosc - Flash OpenSound Control, a Java server enabling communication between Flash and OSC-enabled applications.
JAGS Game Server - Open Source Java / Actionscript 3.0 Game Server - multiplayer sockets, collision detection, keyboards events…
Granite Data Services - Free (LGPL) alternative to Adobe LiveCycle Data Services for J2EE servers.

PHP

Kaltura - KalturaServer is a rich-media assets managements system and a Flash Video processing and progressive-streaming server.
amfphp - Flash Remoting for PHP
PHPObject - Flash Remoting alternative for PHP
SabreAMF - AMF Client/Server library for PHP5
CakePHP - A Rails-inspired powerful and easy to use PHP framework. Can be used to develop flash app backends as AMFPHP is supported through CakeAMFPHP (see below).
CakeAMFPHP - Adapter classes to make AMFPHP work seamlessly with CakePHP. This way, you can leverage your productivity by using CakePHP features on the server side to build your application server and use CakeAMFPHP to send data back and forth Flash/CakePHP. You can also have a HTML version of your Flash app without headeaches.
WebORB - WebORB for PHP is server-side technology enabling connectivity between Flex and Flash Remoting clients and PHP applications. WebORB for PHP can be installed into any PHP5 application to expose PHP classes as remote services. The product provides a complete implementation of the Adobe's AMF0 and AMF3 messaging protocols and thus supports any Flash Remoting or Flex client.
SWX PHP - SWX is the native data format for Flash. It stores data as SWF bytecode. SWX RPC is a remote procedure call protocol encoded in SWX format. SWX PHP is an open source implementation of SWX RPC in PHP. The main advantage of SWX PHP is that it is simple to use and comes with a plethora of APIs that you can use for consuming popular web services. SWX PHP services are compatible with AMFPHP. In fact, SWX PHP uses AMFPHP as a library so you can hit your services via SWX RPC or AMF (by hitting the AMF gateway.

Perl

AMF::Perl - Formerly known as Flash::FLAP, AMF::Perl is an Open Source Perl and Python implementation of Macromedia's AMF protocol.

.NET

Fluorine - Flash Remoting for .NET.
AMF.NET - AMF.NET is an open source alternative to Macromedia'a .NET Flash Remoting. This project is based on both OpenAmf (Java) and Amf-PHP.
http://neutron.sharpstyle.com - Visual Studio 2005 plug-in that lets you code and compile ActionScript alongside your .NET code.
Policy Server - Scalable high performance policy file server for Flash (and coincidently Silverlight). To serve a cross domain policy file on any chosen port, e.g 843, 943 etc. Open source hosted here.

Ruby

rubyamf - Open source application gateway for flash remoting.
WebORB - WebORB for Rails is server-side technology enabling connectivity between Flex and Flash Remoting clients and Ruby on Rails applications. WebORB for Rails can be installed as a plugin into any Rails application to expose Ruby classes as remote services. The product provides a complete implementation of the Adobe's AMF0 and AMF3 messaging protocols and thus supports any Flash Remoting or Flex client.
rubyizumi - An Implementation of RTMP(H.264/MP4) server for Flash video/audio streaming.

Python

PyAMF - AMF support for Python, licensed under the MIT.
RTMPy - RTMP protocol for the Twisted framework.
flashticle - Python library implementing various Macromedia Flash related data formats and protocols (AMF/FLV).
Django AMF - Middleware for Django web framework that enables Flash/Flex applications to invoke Django's view functions using AMF, licensed under the GPL.

Other

OpenLaszlo - Open Source platform for rich web applications that are compiled into SWF or DHTML
(includes presentation server similar to Flex)
SSR - Super Simple Remoting Package for Actionscript 3.
XML-RPC Client - Allows Flash to act as a client to an XML-RPC Service.
laziza - Allows JSFL commands from remote host.
wsdl2as WSDL stub compiler for ActionScript 3
haxeVideo, a lightweight FLV streaming, recording and web conference server written in haXe
swx - A new, SWF-based data exchange format and related tools for Flash.
croqodile - An ActionScript 3 implementation of the Croquet project's TeaTime algorithm for replicated computation.
Universal Remoting- The Universal Remoting group’s purpose is to coordinate and unite efforts on open-source Remoting projects.
STOMP Flash Client- An AS3 implementation of the STOMP protocol that allows socket connections to JMS (Java Message Service) Servers from the Flash 9 player. Use it with the ActiveMQ project - an open source, enterprise quality JMS server with native STOMP compatibility.
unfocus A javascript based tool, with hooks for Actionscript, to enable the browser back/forward buttons and assist with deep linking.
Emotion Machine A interactive intelligent public installation in the stockholm airport to make game and compete with friends.
SQUAT A C template library that binds various kinds of language elements (i.e. Actionscript front-end and C server) to each other through common definitions.

Logging Tools

Alcon - An external output console for Actionscript debugging
LuminicBox.Log - A logging API and output console for ActionScript
As2logger - Logging Framework based on the Java Logging-API
ZLog - *Very* easy log with MTASC and Flash IDE.
Tornado - A runtime configurable logging solution with multiple publishers available.
Zeroi Using any logging system for your MTASC project without having to change the code.
Flash-console - Logger/debugger usable within flash or as remote.
Log5F - The ActionScript 3.0 Logging Utility for Flash/Flex/AIR applications.

Debugging Tools

FlashPreloadProfiler - is an open source profiler for Adobe Flas. FlashPreloadProfiler is made in pure as3 and is design to be loaded over any flash application. It can profile memory allocation, flash internal events, Function Performance, and much more.
De MonsterDebugger - is an open source debugger for Adobe Flash, Flex and AIR. De MonsterDebugger is made in Flex and AIR by design studio De Monsters.
Xray - Logging/debug/Runtime SWF controller
DebugIt - Displays traced data in a seperate SWF so you can debug outside of Flash, while running your application in its shell/production environment.
printrDebugger - Brings PHP's “print_r” to Flash, invaluable once you start to use it. Free, Complete Source Available
Sock4Log - JAVA application which displays traced data from SWF and other (PHP,JS…). Could be a command line or windowed application.
SWFWire Debugger - An open source application for debugging that provides low-level information about method calls.
SWFWire Inspector - An open source application that shows detailed information about the contents of any swf. Provides limited ActionScript 3 decompilation.

Documentation Systems

Acid - ACtion Info Doc, JavaDoc style AS2 doc tool in Python.
as2api - A JavaDoc-a-like for ActionScript 2.0. implemented in Ruby.
ASDocGen - A tool, released under the GPL, that lets you create JavaDoc style documentation for ActionScript code.
NaturalDocs - Documentation system with ActionScript 2 and 3 support
~~mxiFileCreator - Windows Desktop App, for creating and editing (.mxi files) to build MXP files (components and help-material) for the Macromedia Extension Manager.~~ (Project isn't open source, just has a link to external website with no link to download source.)
AS2NaturalDocsAutoComment - A perl script to add NaturalDocs compatible comment stubs to AS2.0 classes. now known as AS2Dac
AS2Dac - A tool that lets you create JavaDoc or NaturalDocs style documentation for ActionScript code. (requires Perl) GPL2
ZenDoc - A web-based documentation tool for ActionScript 2.0 and 3.0 written in PHP using Javadoc code commenting.

See the documentation system comparison.

Flash Players

Flirt - An alternative Flash runtime (pre-alpha)
gameswf library - Even more alternative Flash runtime (pre-alpha)
Gnash - A GPL standalone Flash movie player and firefox plugin supporting many SWF v7 features.
GPLFlash - Another alternative Flash runtime (abandoned in favour of gnash)
Swfdec - An LGPL Flash rendering library that integrates with GStreamer.
MC Media Player - A fully customizable player, very well documented and free!
Lightspark - a modern, free, open-source flash player implementation.