To run Synthclipse you need:
Synthclipse runs on all three major desktop Operating Systems:
You can download the latest version from Synthclipse's SourceForge website. Remember to chose proper version for your Operating System and CPU architecture.
Alternatively you can install Synthclipse from Eclipse using the following Update Site: http://ringojingosden.com/sclipse/update/
Installation is very simple. Just extract downloaded archive and run file eclipse.exe (or just eclipse depending on your Operating System).