This is a plugin I found recently and really enjoy. It gives you the opportunity to redirect several webpages to alternatives. For example Youtube to FreeTube or Piped. If I search for youtube in Firefox, FreeTube automatically opens and shows me my feed. I like it, I use it, I can recommend it.
FastForward has too main parts: URL redirection and Crowd Bypass. URL redirection changes the URL based on a regex (actually, it’s based on JavaScript, but most rules just detect with regex), of which domain redirection is a subset. Crowd Bypass is for link shorteners that give a unique ID for all links. FastForward includes both, including rules for both.
From what I can gather, Fast Forward is more of an alternative to Redirector rather than LibRedirect.
I did some digging: FastForward could specify custom filters during the Manifest v2 days. However Google disallowed executing unpacked/unsigned code in their Manifest v3. This disabled all custom filter lists, and is yet another reason ublock origin isn’t moving to v3.
Isn’t LibRedirect just FastForward/Redirector with baked-in rules?
It’s like comparing apples to oranges, both are fruit but very different. LibRedirect has a nicer UI than Redirector and also has content discovery mechanisms for each of the supported sites as well as the ability to ping each instance and TOR support.
Redirector is just an extension that takes URI, passes them through a REGEX find/replace and then sends the user to said new URL.
I say it’s comparing apples to sliced apples with a slicer. Minus the performing redirection part, LibRedirect is a more polished ruleset generator for redirection extensions.