I am looking form a test automation frameowrk which can work in Clinet/Server architecture (distributed env) and support a mix of operating systems like Windows, unix/linux and Mac I am currently evaluating and looking for only OpenSource solutions, I found just one framework STAF , any help on pointing out other similar framework would be of great help
This is not for a web based application , but for a application using CLI & GUI interface & no proper API layer :(
STAF does seem to be the standard. However if you have something which will handle the distribution for you then it is easy to hook up results gathering. I might suggest starting with hudson which is actually a distributed build tool with some support for testing through the plugins.
The Robot Framework has a remote testing library that uses XML-RPC to send commands from the testing framework to remote servers. It has sample remote servers in python and ruby.
STAF is probably the best option for this sort of thing. It has really good cross-platform support, thorough documentation, and has been pretty stable for years. It's also extensible if you need to customize the services for your own needs.