Fission is a simple editor for compressed files that Rogue Amoeba released this week. It doesn't do much, but what it does, it does quite well. First, the damage: it's US$18 if you already have a valid Audio Hijack license, $32 if you buy it alone. You don't need Audio Hijack to use this. The program is simply a tool that lets you chop up audio files while preserving the original encoding. This allows you to reorder pieces of MP3 or AAC files without transcoding losses, or zap ads, boring bits or silence. The interface couldn't get much easier. The automated tools are few and again simple. There is fade in/out, and it can scan to automatically find and mark silences for you. You can save the final product as a single file in the same format as the original (no additional loss introduced), or into a different format (with transcoding loss, unless you pick a lossless format like AIFF or ALE for output). Transcoding, if you choose it, is done via QuickTime. The program does not support joining files, but thanks to the magic of MPEG frames you can still do this. Take two files of the same format (say, MP3), join them with the cat command from Terminal, and open the joined file in Fission to slice and dice as you please. I've only tried this with a handful of tracks so far, but it seems to work just fine. Unsurpisingly, it can't work with purchased iTunes Store tracks. This isn't a program that's going to change the world, but if you need what it does and don't want a lot of complexity, it's rather nifty.