I'd like to know if there are any base SaaS type systems out there in the open source world.
Trying to find implementation options for a new SaaS type product that is being worked on. Java solutions would be preferred but all are welcome.
For example: Basecamp will let you sign up for a service and they provide you with a yourdomain.basecamphq.com. Obviously the code base is the same and it just routes and deals with the data based on the incoming 'yourdomain' wildcard. There are some basic color changing options from what I can tell as well.
Another Example: StackExchange is similar. You can create a StackExchange hosted site that is run on the same machine and uses the same application instance that is powering other stack exchange sites.
I'd like to get examples of codebases with this feature in the open source realm.