Last week, Adam Smith of Convea asked me to take a look at their product, Convea. I didn't have time to look at it until now, but I am glad I did. At first glance, it was a just another open source web-based groupware. Their list of business and technical benefits made me glaze over like the sides of a cereal box. Tiny screenshots didn't help much either. So it wasn't until I tried the demo that I uttered "Wow!" just as I have when I saw Oddpost first time.
They had done a great job of simulating Windows UI cleanly. Playing with it, it was difficult to keep in mind that this was all done in DHTML, the language of torture if you are a perfectionist. While overall integration could use improvements, you can easily tell that countless hours of hard work went into it.
Convea is open source and GPL version is available for free. To lift the GPL curse so you can use it on your commercial website or intranet, you'll need a Standard Commercial License ($1995). To develop commercial products with it, you'll need a Commercial Services License ($9995). Oh, it's ASP-based currently although there seems to be talk of PHP and ASP.NET versions.
Disclaimer: Having spent most of past 20 years helping startups, I enjoy helping them get their message out through my blog. I won't call something bad good, but I felt my readers should be aware of my sympathetic bias toward startups. Also, if you are a startup and think you have a great product but not enough exposure, let me know.
Update: The demo requires IE 5.5+.