FLAC first emerged in 2001 as an open-source alternative to other lossless formats emerging at the time. These included Apple Lossless (ALAC), Microsoft's WAV (Waveform Audio Format), and WMA Lossless. But these competitive formats do have their disadvantages. While ALAC has a loyal following among iPod and iPhone users, it hasn't seen much uptake outside of Apple. The WAV format is more popular, and it's also compatible with iOS devices, but its biggest problems are that file sizes are very large and it can't retain "tag" data -- artist, album name, lyrics, and so on -- in the way the other formats can. FLAC, on the other had, not only supports tags but is also compatible with many different types of equipment -- minus one as we'll see, though there are simple workarounds.