Release note details are in the "Change Notes" tab. There are many more changes that went into this release than mentioned in there. I will try to go back and add more of the significant changes.

The release from v0.1.1a (steam v1) to v0.2.4a (steam v8) was significant (e.g. 9 new technologies).

There were no Steam releases inbetween. All the other releases were internal and test (unstable) releases.