TwistedWave is a very easy-to-use and powerful audio editor. It supports Audio Unit plug-ins and many file formats, including wav, aiff, caf, mp3, mp4, FLAC, and Ogg Vorbis. It has good multichannel support, so you can apply Audio Units to a selection of channels. It supports unlimited undo and redo, which work instantly. Zooming in and moving around the waveform is very fast, even with very large files. All the effects are applied in the background, saving a lot of time.
Tag is a metadata editor for FLAC, Ogg Vorbis, Monkey's Audio, and WavPack files. Tag has an intuitive interface that simplifies common editing tasks while also allowing direct manipulation of tags. Tags can be dragged between files, or Tag can add all the tags contained in one file to another in one fell swoop. For files with incomplete or missing metadata, it can guess tag values by matching the filename to a user-defined pattern. It can rename files by substituting tag values into a user-defined pattern. It can edit multiple files simultaneously, eliminating repetition and saving time. It features customizable mappings that allow you to specify which tags are mapped to the various fields in the user interface.