The FrameMaker eco system
Adobe InDesign, Illustrator and a other mainstream layout and dtp applications have a vast eco system. There are literally millions of premade InDesign templates, Illustrator stock drawings etc to be found in the vast stock databases. Not so when it comes to the users of Adobe FrameMaker, RoboHelp and Captivate. The user of the Adobe TechComm products have a rather small selection of service providers to choose from and an ever smaller selection of add ons like scripts, stock etc. Especially the lack of creative content is probably a big hindrance for attracting new users.
The Adobe TechComm Partner portal.
Here you can find companies working with Adobe TechComm. The search function on the site is not superduper, but it is there.
https://partners.adobetechcomm.com/
The Adobe FrameMaker support community
Frameexpert.com
Rick Quatro of Frameexpert.com writes scripts which can help you do all sorts of useful stuff in FrameMaker, like cleaning up all tables or write out the entire list of pargraph styles. His "Archive" script which can archive an entire publication is wonderful!
https://frameexpert.com/store/index.html
Klaus Daube
There may be people who know more about FrameMaker than Klaus Daube, but I rather doubt it. His Compendium on all things FrameMaker is excellent and will answer lots of intricate questions. He is also the developer of scripts and plugins, like the improved toolbar
https://www.daube.ch/docu/fmaker00.html
Here you can find the Compendium and lots of other nice scripts! https://www.daube.ch/docu/fmaker00.html#genlists
TechComm Tools
Matt Sullivan is the author of a great number of books on FrameMaker. They are indispensable reference works and he also
https://techcommtools.com/
Silicon Prairie Software
Siliconprairiesoftware develops small useful plugins for FrameMaker. Lots of goodies!
https://www.siliconprairiesoftware.com/index.html
Leximation
Leximation develops plugins and are - as far as I know - the only ones to do plugins for structured FrameMaker
https://leximation.com/
Westreet Consulting
Weststreet Consulting develops plugins. Some are superspecific and very useful like the Xref wizard which will help you fix broken cross references.
http://www.weststreetconsulting.com/default.html
FrameMaker.dk
is Bjørn Smalbro and the worlds only shop for FrameMaker templates. I do all sorts of technical documentation/design consulting.
https://framemaker.dk/en/shop
Rocky Mountain Training
Rocky Mountain Training and Barb Binder. She does training in FrameMaker, InDesign and lots of other programs. Here you may also find a truly big blog with lots and lots of useful FrameMaker tips and solutions!
https://www.rockymountaintraining.com/