The following are various pieces of software that I've written and have made available as GPL licensed Open Source Software. If you have any questions of comments about any software I've written feel free to contact me at charles@thedigitalmachine.net.
Miscellaneous
Calculon is a little command line calculator, I wrote to for the calc library but it's a useful tool on it's own. It can calculate derivatives and functions. You will need the lemon parser generator, makeheaders, and re2c to compile it.
VoIP Related
A simple DTMF decoding library, runs on Linux but could be made to run on Windows with a little work.
A very simple STUN library. It doesn't yet support all STUN features, could be used as a starting point for a more complete STUN library.
A Fixed-Point voice echo canceller, based on an Open Source floating point ECAN. More improvements are required before it reaches an acceptable voice-quality level.
Linux Drivers
Alternate AMD Au1000 GPIO Driver, and Header File
An alternate (there already is one in the Linux kernel but I didn't like the user level interface) GPIO Driver for the AMD Au1000 processor.
An ALSA (Advanced Linux Sound Architecture) Driver for the AMD Au1000 Processor. As of Linux version 2.6.10 it is part of the kernel.
AMD Au1000 Ethernet Driver NAPI Patch
A patch to the base Linux Ethernet Driver for the AMD Au1000 Processor that adds NAPI (New-API).
Scripts
A Makefile that will download all of the source code required to build an embedded toolchain for Linux, and then build it. I've only tested it with a mipsel compiler and linking to uclibc but in theory it should work for any architecture.
This is a very small script that I use to spell check, clean-up and upload this web-page. It uses aspell and wput.
Patches to Open Source Software
Patch to the ALSA 1.0.5 Library that makes it possible to compile it linking to the uClibc library.
Patch that adds an echo canceller to Linphone 0.12.2. It's kind of hacky and doesn't work very well. It will take some effort (from you) to get it working.
Removes "Warning - approaching max data size" when running under cygwin.