Facetmap
Available at http://facetmap.com
The technology
Java library with custom MySQL and Postgres relational mapping
Website in Spring framework with JSP pages, in Tomcat app server
XSLT version of Facetmap, wrapped by PHP and ASP for use in those webservers
The story
This was a solo product I developed mostly in 2001 and 2002 to demonstrate faceted classification. (Faceted classification is a kind of data markup that gives users more options in navigating the data. For more about that, see the original demo.) Basically, a user uploads or publishes her own classification, and Facetmap uses that to construct a web-based navigation interface for her data.
It also serves a primitive HTTP API for third-party clients: Facetmap's XML responses could be parsed, or formatted with XSLT, for display by the third party. I was pretty happy when one of my users donated his XSLT back to me and I got to use it on the Facetmap site. (It's the "Nav Column" presentation style.)
Facetmap fueled some contract work and I sold some licenses, but here are my points of more pride:
Various university courses use this product. Professors instruct their students to write a classification and submit it to Facetmap so it can be browsed. The students write me every so often -- usually asking me to troubleshoot something, but I like the communication anyway.
It led to my only speaking engagement to date. That was a lot of fun but I learned that I'm not going to make a career out of presentations. I spend too much time preparing them.
Cloud services feel natural now, but I published Facetmap such a long time ago that few people were willing to upload their data to a third-party hosted service. Salesforce and the term "SaaS" were only a year old and not well known, certainly not to me. So I count it as innovation. I take unjustified pride in innovating things which later prove to be popular, even when I had nothing to do with their popularity.