In the interest of remaining chronological, I am deferring a description of my iMac and iPad synthesizer software. In the 90s my first serious electronica investment was a wavetable sound card that cost around $245 and had memory slots for 2 MB of memory which was more than I had on my motherboard at the time! The AWE32 sound card from Creative labs gave me wave table synthesis which was worlds better in sample quality than the cheap FM synth cards that were prevalent on most PCs.
I remember getting software to use my computer keyboard as a monophonic "piano" as well as getting software to create soundfonts. Using Cakewalk LE I was able to put together rudimentary tracks of sampled music and better still, was able to sample my kids voices, pop them onto a keyboard and "play" them as instruments.
I don't have anything I created at that time that was worthwhile to keep, but it was a blast learning how to make/shape sounds and build up soundfonts into instruments.
It wasn't until years later that I left Windows for more Mac based software - and I didn't care at all for Macs until the release of OS X. My own hardware at the time ran either Windows 9x or Linux (pre 1.0 releases).
For music options, though, there were at that time very few open source options so it was Windows or Mac.