Development Tools

IDE's

 * Eclipse
 * NetBeans
 * JBuilder
 * Oracle JDeveloper and JavaMe Extensions
 * IntelliJ IDEA
 * Extransit Mobile Interaction Suite

Eclipse Plugins

 * EclipseMe EclipseME is an Eclipse plugin to help develop J2ME MIDlets
 * Aplix JBlend Emulator Plugin Aplix provides a JBlend emulator plugin with debugging support.
 * Nokia Carbide Nokia's Carbide-J suppies both emulator plugins and plugins to integrate with Nokia's WTK toolkits.
 * Nokia's JavaME Devlopers Library Nokia provides a JavaME Developers Library in Eclipse Help format as an Eclipse plugin.
 * SonyEricsson Device Explorer SonyEricsson provides a Device Explorer to control the Java Application Manager on a SE device from Eclipse.
 * SonyEricsson CDC plugin SonyEricsson proiveds a CDC Eclipse plugin. Requires the UIQ 3.0 SDK from UIQ and the SymbianOS UIQ SDk from SE to use.
 * BenQ(Siemens) BenQ provides as part of the SMTK 3.0 install Eclipse plugins to integrate their SMTK with Eclipse.
 * Vodafone v-apppli 1.2.2 emulator plugin Vodafone KK provides an Eclipse plugin for the v-appli 1.2.2 emulator.
 * NEC-MFriend NEC at MFriend provides Eclipse plugins for some of its emulators, simulators, and SDKs. Requires free registration to download.
 * VistaMax Wirelexsoft provides VistaMax an IDE for MIDP development that handles weird stuff like BlackBerry(RIM) and is based on the Eclipse platform

NetBeans Plugins

 * Mobility Pack Mobility Pack is an extension for development of J2ME MIDP/CLDC applications.
 * Mobility Pack for CDC Mobility Pack for CDC is an extension for development of J2ME PP/CDC applications.
 * NetCaboodle NetBeans Business 2 Mobile plugin The Business 2 Mobile plugin from Net Caboodle makes it easy for you to develop MIDP clients for your business services, without the need to write any of your own protocol code

Optimizers / Obfuscators

 * mBooster mBooster is a professional J2ME Optimization Suite, featuring a true optimizing J2ME compiler, a custom-built preverifier, declarative resource packing, and the world's best ZIP and PNG recompression algorithms. The optimizing compiler performs extensive intraprocedural and whole program optimization, including method inlining, class merging of instantiated and static classes, redundancy elimination and local variable sharing, along with many more traditional optimizations. mBooster automates most of the best practices described in Give me all your tricks for minimizing jar file size.
 * ProGuard ProGuard is a free Java class file shrinker, optimizer, and obfuscator.
 * yGuard yGuard is a free Java Bytecode Obfuscator
 * RetroGuard RetorGuard is a GPL'ed Java Bytecode Obfuscator

Java Technology

 * Sun Downloads Archive no longer supported products

Porting

 * J2ME Device DB and Microcode framework Device database (over 300 devices supported) with framework for multi-device development and deployment

Emulators

 * deviceanywhere.com Uses a Java app on your computer to remotely access real phones across multiple carriers. Costs $$$ but cheaper than buying all of those phones yourself.
 * me4se.org Runs a MIDlet in a Java Applet on a Web page or in regular J2SE.
 * microemulator Similar to me4se but without MIDP 2.0 support and a less restricting license.
 * mPowerPlayer Provides an emulator and SDKs. For Mac OS X users this is the SDK and Emulator sets you need due to limited (or non-existing) Mac OS X support from other OEM SDKs and Emulators. Also supplies a free Flash-based environment to run midlets in a web browser.

Building

 * ANT ANt build tool.
 * antenna Provides wtkpreverify, wtkpackage, wtkjad tasks etc. for ant. Also integrates with some major OEM SDKs and emulators including SUN WTK, BenQ-Siemens, RIM BlackBerry, and etc.
 * J2ME Polish Is an advanced build tool for J2ME games including a game engine, logging, and etc using the ANT build framework. Also a includes a high level UI API.
 * Maven Maven also has JavaME plugins to wrap our favorite tools in building JavaME applications.
 * Maven Antenna Plugin Maven wrapper to use Antenna in the Maven build environment.
 * Mojo Mojo runs the preverifier from the specificed SDK in the Maven build environment.

Unit Testing

 * JMUnit Provides jars for both CLDC1.0 and CLDC1.1 unit testing along with manual and source.
 * J2MEUnit Provides a testing framework for J2ME MIDP and is based on Junit.
 * Gunjan Doshi's 10 Minute J2MEUnit Tutorial Gunjan Doshi's 10 Minute tutorial on using J2MEUnit.
 * Mobile JUnit SonyEricsson provides Mobile JUnit which integrates with their WTKs/SDks to provide unit testing on CLDC devices and within their WTKs/SDKs. Can be used with other WTKs/SDKs other than SonyEricsson's.

SDKS and WTKs

 * Java ME downloads Sun Microsystems downloads for MIDP CLDC WTKs, CDC WTKs, and reference implementations(RIs), specifications, and documentation.
 * mPowerPlayer Provides an emulator and SDKs for free and often is current with supported apis and has MacOSX binaries.
 * BenQ Developer Portal Provides SDKs for BenQ(formely Siemens) handsets. Requires free membership registration to download SDKs.
 * MotoDEV MotoDEV combines the former MotoIDEN and MotCoder JavaME developer programs into one site to obtain the latest SDKs for all Motorola handsets. Requires free membership to download SDKs.
 * SonyEricsson Provides SDKs and emulators for SonyEricsson handsets. The CDC emualtor requires an UIQ 3.0 SDK which can be found at UIQ Developer Site.
 * Forum Nokia Provides SDKs and emulators for all Nokia handsets. Those with s60 devices from non-Nokia OEMs can use the s60 MIDP development SDK and emulators to target these devices.
 * Samsung Developers Club Provides SDKs and emulators for all Samsung handsets. Site does not work in any non MSIE browsers.
 * Doja Developer Network Provides Doja(i-mode) SDKs and emulators for i-mode handsets and only has the English SDKs and emulators. More SDKs and emulators can be found at the NTTDocomo English page and the NTTDocomo Japaneese page. A diagram showing CLDCL version and handsets supported by SDK version can be found on the Doja Wikipedia page.
 * Vodafone KK JSCL and VFX Provides SDKs and emulators for JavaME with JSCL and VFX extensions. JSCL is the M3G subsitute. Note: Click the url link that has the privacyletter in the url and you will be presented with two acknowledgement screens that you will click the left bottom button on and than you will be asked to fill out a form(company name, your name, email, email) and fill it out and click left bottom button to get to the sdk/emulator download.
 * WIPI SDKs from WIPI Boards WIPI is s JavaME standard on top of Korean i-mode known together as WIPI. This forum site provides SDKs and emulators acessible to non-Koreans as Korean Telekoms limit access to SDKs and emulators to Korean citizens only. LG does provide accessible SDKs and emulators at their LG Telecom WIPI Developer Site SDK Support page, however it is the only OEM I know at the moment to do so at this time without the Korean Citizenship requirement for access.
 * Sprint Developer Provides WTKs in addiiton to the iDEN SDKs and emulators from Motorola and RIM that target devices on the Sprint network.
 * Cingular devCentral Provides emulators for devices on the Cingular(formely ATT) mobile network.
 * BlackBerry Blackberry provides RIM SDKs, emulators and Java IDE for RIM development.
 * Danger Sidekick Danger provides SDKs for the Sidekick J2ME CLDC compliant devices.
 * NEC SDKs at MFriend NEC SDKs for JavaME targeting NEC devices. Requires free registration for downloading the SDKs.

Programming Libraries

 * J2ME Polish High level UI API, build system and a lot more. License: GPL, commercial license available
 * kXML XML and WBXML parser for J2ME. License: BSD

Graphics

 * Custom Colour Depth Converter - Adobe® Photoshop® compatible colour reduction plug-in (More Details).
 * GraphicsGale - Sprite Editor.
 * J2ME Animation Tester - Tool for viewing 'filmstrip' animation images (More Details).
 * OptiPNG - Tool for optimising PNG files.
 * PNG Crush - Tool for optimising PNG files.
 * PNGCrusher - Tool for optimising PNG files (OS X).
 * PNGOUT - Another Tool for optimising PNG files (WIN32). (said to be the best at the forums)
 * PNGGauntlet - Nice GUI for PNGOUT (.NET 1.1).
 * PNGQuant - Command-line colour reduction tool for PNG images.
 * Blender M3G export for J2ME A python Blender extension to export 3d to m3g for J2ME 3D gaming.

Level Editors

 * Mappy - Tool for creating level maps for games.
 * TileStudio - Tool for creating level maps for games.
 * Tiled - Tiled, a generic tile map editor

Libraries

 * JavaMappy - JavaMappy is the Java playback library for Mappy.

Music
Composing tools (sequencers and trackers)  Converters and wav-editors 
 * The Jazz Midi Sequencer - Freeware MIDI sequencer for Windows and Linux.
 * Anvil Studio - Free sequencer
 * MadTracker - Free tracker, has midi export option.
 * MidiTracker - Commercial MIDI tracker
 * Modplug Tracker - Free tracker, has midi export option.
 * ztracker - Free MIDI tracker, modeled after Impulse Tracker. (seems to have a problem saving instruments?)
 * TS-MIDI Editor - Freeware MIDI editor
 * Audacity - The free, cross-platform sound editor
 * Super - Can convert sound files to AAC (and a wide range of other formats)
 * Miksoft's page - Has converter tools like mp3 -&gt; amr and vice versa.

Screen Capture software

 * AutoScreenRecorder form Wisdom-SsoftFor making those demo AVI's (A free version is also available!)