There are more out there, but these are the primary tools I use when working with FAST for SharePoint.
- QR Server debugging queries >> Use this to inspect queries coming from SharePoint to FAST.
- FFD Dumper for inspecting crawled properties >> Use this to inspect crawled properties
- MossMan FAST Query tool >> A handy little tool which allows you to build queries yourself, and interrogate FAST. Useful when writing custom FAST control.
- FASTSearch2010.chm >> A downloadable MSDN reference which holds a ton of PowerShell commands that relate to configuring FAST
- Information Worker Demo VM >> Downloadable VM from Microsoft that is setup and ready to use. Comes with FAST 4 SharePoint preconfigured
- PowerGui >> IDE for working with PowerShell. Invaluable if you’re working with PowerShell for a longer period of time.
- FAST Query Logger >> A new tool which makes working with the QR Server significantly easier.