I use the Spin IDE in Windows XP in VirtualBox. It's a little weird, but it's been very reliable and it was free. Honestly it's easier to keep this freaky VM frozen in time than keeping a modern development environment up to date.
Luckily they haven't updated the Spin site in 10 years, so it still works with IE 8 and you can even pull stuff down from there straight to the VM.
I write code and manage the files in a Mac editor and just paste it into the Spin IDE to compile and flash the spin dev board.