I feel like Claris could have been much more successful had they broken away from Apple sooner. I'm guessing they lived in some sort of bubble though because th

I feel like Claris could have been much more successful had they broken away from Apple sooner. I'm guessing they lived in some sort of bubble though because the main devs who left Claris in the 90s went on to build software for BeOS instead of Windows. Are there any software companies that have had lasting success selling software exclusively for a niche OS like Apple's (either Mac OS or OS X)?