jPresto
- Shrinks and obfuscates code for the J2ME platform. [Commercial]
- http://www.s5systems.com/jPresto.htm

IBM WebSphere Studio Device Developer
- An integrated development environment for the creation and testing of applications that will be deployed on handsets and other small devices. [Commercial]
- http://www.ibm.com/software/wireless/wsdd/

Sun Wireless Toolkit for CLDC
- A toolbox for developing wireless applications including emulation environments, performance optimization and tuning features, documentation, and examples.
- http://java.sun.com/products/sjwtoolkit/

WebSphere Everyplace Micro Environment
- For creating advanced embedded solutions, by IBM.
- http://www.ibm.com/software/wireless/weme/

mBooster
- A suite of J2ME size and performance optimization tools designed for both MIDP and i-Appli development. [Shareware]
- http://www.innaworks.com/

Mobile Device Tools for J2ME Developers
- A set of Java MIDlets that allow developers to quickly learn the specifics of new devices. [Open source, MIT License]
- http://mobiledevtools.sourceforge.net

NetBeans Mobility Pack
- For NetBeans IDE to write, test, and debug applications for Java technology-enabled mobile devices.
- http://www.netbeans.org/kb/articles/mobility.html

Antenna
- Provides a set of Ant tasks suitable for developing MIDP Java applications.
- http://antenna.sourceforge.net/

J2ME Polish
- A suite of tools for creating "polished" J2ME applications. Each tool meets a definite need of J2ME developers: Build-tools with an integrated device-database, a powerful GUI, a localization framework, a game-engine, a logging framework and a co
- http://www.j2mepolish.org/