How can I read Atari formatted disks on a Mac?

Atari initially used single-sided disk drives that could store up to 360 KB. Later drives were double-sided versions that stored 720 KB. Due to the early sales of so many of the single-sided drives, almost all software would ship on two single-sided disks instead of a single double-sided one, for fear of alienating early adopters. ST magazines wishing to cater to the entire audience while still supplying a large amount of material on a single cover disc had to adopt innovative custom formats to work around this problem. Another sticking point was that while the Atari double-sided drive could read IBM-formatted disks, IBM PCs could not read Atari disks. This was a formatting issue that was later resolved by third-party software formatters and TOS upgrades (1.4 and higher).