Java & Processing

• NetUtil OSC Library for Java Compact and efficient java library for sending and receiving messages using the OpenSound Control (OSC) protocol
• MaxLink Java libraries enabling communication between Processing (Java) and Max/MSP (made quite good experiences connecting Java applications with Max (4.x & 5) patches. Recommended!)
• oscP5 OSC implementation for the programming environment Processing
• OSC communication between Max and Processing (triggered by Midi controller) Tutorial by Ash Oakenfold

Mobile (input) Devices

• Mrmr for the iPhone/iPod Touch mrmr is an open-source research project to develop a standardized set of protocols and syntax conventions to control live installations and multimedia performances via mobile devices (demo video on youtube)
• TouchOSC iPhone / iPod Touch application that lets you send and receive Open Sound Control messages
• OSCemote Remote control application for the iPhone and iPod Touch (check the examples)
• OSCulator Another software linking controllers to music and video software
• oscpack Set of C++ classes for packing and unpacking OSC packets

Misc.

• OSC-tagged bookmarks at delicious.com
• OpenSound Control Home Page University of California, Berkeley
• opensoundcontrol.org Center For New Music and Audio Technology (CNMAT), UC Berkeley
• LusidOSC Open source initiative to define and support a layer for unique spatial input devices using OpenSound Control

If you like to recommend projects or resources that are not listed below, drop a comment. Any recommendations and helpful hints are much appreciated.