Snow Leopard with Ruby 1.9 and Rails 2.3.5

I’m working my way through “Agile Web Development with Rails - Third Edition” and the latest version of the PickAxe “Programming Ruby - Third Edition” books of the Pragmatic Programmers.
As Snow Leopard is my OS I need to update the default shipped Ruby and Rails versions to get to Ruby 1.9 and Rails on top of that.

I’ve been installing and uninstalling multiple things before finally settling on my ultimate recipe for installing the correct Ruby version and Gems:
(Within Terminal and already running the latest version of macports )

sudo port install ruby19 +nosuffix
sudo port install sqlite3
sudo gem update --system
sudo gem install sqlite3-ruby
sudo gem install rails

Great Visual Diff/Merge tool for OSX

Back when my primary dev-environment was Microsoft I would use the open-source tool WinMerge for all my Diff/Merge needs. Great tool, good performance, does the job.
Now that I’ve switched to the Mac I had to find a new visual Diff/Merge tool, and I want it cheap, or better free :)
Searches in the past didn’t turn up any satisfying results, but I think I’ve found the tool to do the job. Sourcegear, a company I knew from the past for their Vault product, which is a compelling replacement of Visual SourceSafe, has been so kind to distribute their Diff/Merge tool as a standalone and free cross-platform tool.
Downloaded, used it for comparing and merging FAST indexprofile files (which are plain XML), loving it.
Oh, I’m not affiliated to Sourcegear in any way, just like their Diff/Merge tool on OSX.