Ureka is a collection of useful astronomy software that is generally centered around Python and IRAF. The software provides everything you need to run the data reduction packages provided by STScI and Gemini.
A list of included packages is available here.
Individuals who have used scisoft at some point are strongly encouraged to remove any references to it from their login scripts to avoid conflicts.
When using Ureka for the first time, run
Answering 'yes' to the prompt will add two functions,
ur_forget, to your login scripts as described in http://ssb.stsci.edu/ureka/1.0beta5/docs/usage.html
Then you should be able to simply call
ur_setup to begin using Ureka.