I spend a lot of my time on computer software. Here are various personal projects I've had.

GovTrack.us is a nexus of information about the United States Congress, primarily tracking the status of legislation. GovTrack lets you monitor your representatives and legislation in topics that interest you through email updates, RSS feeds, etc. The site was mentioned in the NY Times and the Washington Post. The site pretty much runs itself. Some 15,000 people visit the site each day. More about this aspect of my life on my civic tech page. (Since 2003.)

The Penn Lambda Calculator is a linguistic semantics pedagogical tool made in conjunction with Lucas Champollion and Maribel Romero. (2006-2007.)

Praat-Py is an extension to the Praat program for phonetic analysis that allows scripts to by written in Python. (2007-2008.)

SemWeb .NET Library is a .NET library written in C# for working with RDF data for the Semantic Web. It's used in the Gnome application F-Spot, and possibly elsewhere. (2005-2009.)

RDF datasets: A 1-billion triples RDF database of U.S. Census statistics, basically the largest open, linked, and dereferencable RDF database of real-world information that exists. Datasets for the U.S. SEC and Congress. I also write an introduction to RDF which you can find at that link, on my site rdf:about.com. (2006-2008.)

Sender Verification Extension is a Mozilla Thunderbird extension for verifying the domain name claimed in the From: address of emails using SPF and DomainKeys, as a tool to combat phishing. I'm not actively developing the extension much, mainly just maintaining it. Apparently some 10,000 people are using the extension and it has been downloaded 75,000 times since 2004! (2006-2007)

Lighthouse IMAP Integration: Email integration for the Lighthouse ticketing system.

Other projects that I contribute to: I wrote the initial support for Subversion integration for MonoDevelop but am not involved with it now, and I contribute to mod_mono since I need it to work for GovTrack.

Some other things that I created but no longer maintain: Diff C# library, PerlSharp (Perl interpreter bindings), SvnWebView (CGI/Perl script to browse a SVN repository).