I just upgraded my MacBook Pro from Tiger to Leopard this weekend. No, Tiger was working fine but I wanted to have the latest Mac OS like everyone else, so what the heck. The installation went very smooth thanks to a nice blog post over at Redline Software. I backed up using SuperDuper and booted off the backup to make sure it worked, and it did.
I use my MacBook Pro to write Ruby on Rails applications and use both SQLite3 and MySQL. It appears as of this writing there is not a pre-packaged release of MySQL which is supported under Leopard. There appears to be some inconsistent behavior I didn’t want to have to deal with. I found a great blog post from Hivelogic called Installing MySQL on Mac OSX. This post was dead-on and saved me a ton of time and I hope this post will guide you to solving your problem.