Best OSX 10.5 apps

MAX is likely the closest equivalent to EAC you'll find for OS X.

For text editing, Editra is a free python based developer's text editor with all your expected text manipulation functions (syntax highlighting, block folding, regex search and replace, column editing mode) and an extensible plug-in interface (including a Projects plug-in that adds IDE-style project management).

On the BitTorrent side, you should know that uTorrent has a Mac OS X port available now. You might check that out.

Vine Server is a excellent free VNC server that offers more flexibility that the built in Screen Sharing services of Leopard, including on-the-fly JPEG compression, and adjustable bit-depths.

If you like to geek around in the Terminal, MacPorts is a must-install. Even though OS X 10.5 is fully certified UNIX, and is fully POSIX compliant (meaning for many *nix sources you can download and build them without modification to the source), MacPorts makes building and installing *nix software faily straitforward with both a command line interface (port install packagename) and a GUI front-end for package management. MacPorts installs everything in a separate /opt/ directory, keeping the main unix filesystem clean and making MacPorts removal utterly painless.

MacFUSE is another consideration if you have a need to read/write from NTFS volumes. Its a port of the Filesystem in Userspace project, and allows you to mount all kinds of filesystems which are then made available as if they were like any other volume.

Jam it back in, in the dark.