I know many of you have been wondering why Mac foobar2000 is essentially 0.5 versions ahead of Windows.
The long explanation is that initial port was based on an early foobar2000 v2.0 prototype from 10 years ago, hence named 2.0, even though it was eseentially foobar2000 mobile codebase. This was foobar2000 for Mac up to version 2.3.
Windows foobar2000 v2.0 was entirely rebooted later starting from 1.x source. Given choice between releasing another foobar2000 v2.0 for Mac or using different versioning on Mac/Windows, I opted for the latter and released proper foobar2000 v2.0 for Mac as v2.5.