I'm currently using Framemaker 2017 at home, and some of the people at the company I work for are using Framemaker 12. If I save my work as an .fm file, will my coworkers be able to open them in Framemaker 12 with document formatting intact?
They won't be able to open the 2017 files directly. You will have to save your files as MIF 2017 and they can open those in Fm 12.
So if I save a document as a MIF 2017 file, will my coworkers be able to check master pages / formatting and be able to interact with it like a normal Framemaker file, or will it be read-only or have limitations?
re: So if I save a document as a MIF 2017 file, will my coworkers be able to check master pages / formatting and be able to interact with it like a normal Framemaker file, or will it be read-only or have limitations?
If you have avoided using any FM document features not present in FM12, there should be no problem with full round-trip collaborative work. MIF is merely a human-readable markup that encodes everything in the binary .book or .fm file. This includes Master and Reference pages and their content. MIF files are read/write by default.
Older FMs just ignore any markup they don't support. They may or may not preserve it on re-save.
If you go back far enough, there are intractable issues. FM7 or earlier can't handle the Unicode present in FM8 or later. Expect serious document damage in that scenario.
As per Bob, yes, as long as you limit yourself to features found in Fm 12. Since this sound like MIF is new to you here is a brief description from Adobe:
MIF (Maker Interchange Format) is a group of ASCII statements that create an easily parsed, readable text file of all
the text, graphics, formatting, and layout constructs that Adobe® FrameMaker® understands. Because MIF is an alternative
representation of a FrameMaker document, it allows FrameMaker and other applications to exchange information
while preserving graphics, document content, and format.
Hope that helps.