Red Emma's has developed a number of free software programs to help carry out our operations, which we are happy to contribute to the digital commons.
Our first point of sale system, used for nearly a decade, and written to support the needs of a tiny low budget retail establishment that needed to track inventory well enough to do effective consignment and construct intelligent orders from a massive amount of independent book vendors. Written in python, with a GUI fronted and a web backend. Totally and completely obsolete, and you shouldn't use this, although it's very possible that a number of infoshops around the world still do.
We learned a lot from infoshopkeeper, and when we decided to expand Red Emma's, we rewrote it from scratch as a modern Ruby on Rails web application, capable of better modeling the way bookstores need to work, supporting neat collaborative order building, building in all sorts of sophisticated analytics, and providing us with a basic web cms. You are looking at it right now. It's awesome, although had we any sort of budget for software development the whole time we were writing it we'd probably have abstracted out the Red Emma's specifics from the system a little more!
After banging our heads against recalcitrant Drupal plugins for a year or two, we decided to rebuild the website and course scheduling system of the Baltimore Free School as a Ruby on Rails app. It works ok, although probably is due for a rewrite soon.
If you'd like to use some of this software, but don't know where to start, or need custom programming done to adapt it to your needs, we can probably work out some kind of consulting contract. Get in touch at info-at-redemmas.org.