Like many Mac users, I upgraded to Snow Leopard on Friday and overall it was a good experience. Some aspects of daily use are definitely 'snappier' now and I do seem to have a good deal more disk space available than before. I had to uninstall some HP software to get my printer/scanner working smoothly but that was the only glitch with peripherals.

I was somewhat surprised to find that I could no longer compile some of my Java projects though. It turns out that Snow Leopard includes Java 1.3 and 1.6 but not 1.5. It actually creates symlinks from the 1.5/1.5.0 directories to the 1.6.0 directory. Unfortunately Java 1.6 is not backwardly compatible with 1.5 (well, the language mostly is, but there are significant differences in some APIs).

If you are impacted by this issue then the good news is that it is very simple to resolve. You simply need to restore the 1.5.0 directory from your backup. This was very simple with time machine, and it was good to have a reason to finally try out a time machine restore.