There's a list of mage patch notes that includes beta changes
here, and I imagine you can find them for the rest of the classes on that site too.
Of particular note is the 0.9.0 patch, which was widely seen as "the big mage nerf" patch and I swear half the retards that play this game still wanted us to go back to the pyro-rape days of 0.8.0 until the big buff in 1.11. (In context: the level cap at 0.8.0 was 50.)