Aside from Garage Band, there are many different companies that provide software compatible with a Mac. For instance, Pro Tools was originally designed to work on a Mac, and many users find that it is still better suited to run on a Mac than a PC. Other sound recording options that you may already have for your Mac include: Wire Tap Studio, iMovie, WavePad, and Final Cut Pro.
Other than Apple programs, the following programs are available in Mac format: Audacity, Cakewalk, Cubase SX, Jasmine, Logic, Reason, Sound Studio, Steinberg Nuendo, Amadeus, Audiocorder, Audio Hijack, Boom Recorder, Call Recorder, Coaster, Final Vinyl, Mackie Tracktion, Pure Vinyl, PreSonus, QuickVoice, recorder.xhead, Sound Studio, and Voice Candy.
Many of the same software programs are available for both Mac and PC; however, there are some that are PC-based only, such as Sony's ACID music programs. The following recording software is available for a PC: Samplitude, Soundforge, Cake Walk, Cool Edit Pro, Audacity, Pro Tools, Logic, Cubase, PreSonus, Ableton, Motu, Image Line FL, Acoustica, Steinberg Nuendo, n-Track, Anvil Studio, Quartz Audio Master, Synapse Audio Orion, Mackie Tracktion, as well as a myriad of new software becoming available every day.
There is a vast array of audio recording software available to download for free on the Internet. Although there is a wide variety as far as quality is concerned, there is no reason to avoid this route, especially if you are not ready to invest a lot of money into music software yet. For quality-control purposes, the following programs have received good reviews from users: Audacity, Krystal, Quartz Audio Master Free, Anvil Studio, and FreeCorder. Also keep in mind that if you are interested in purchasing a certain software, most companies have free trial downloads that last anywhere from a few weeks to a few months.
Ultimately, you will want to do some research on your own. For instance, do you just want to record your audio? Do you want to import midi files too? Mix them? Does your computer have the necessary requirements? All of these things will determine which audio recording software program is best suited to your needs. A quick Internet search will help you to narrow down which program you would like and where to find it.