Silent Garfield was invented first, on a forum called Truth and Beauty Bombs, which was the fan forum of a webcomic called Dinosaur Comics, though the discussion thereon tended to be only tangentially connected to Dinosaur Comics.

The thread in which it was invented became a big deal and "went viral". I think Garfield Minus Garfield was also invented later on in the same thread, as well as some other variants. But Silent Garfield is funnier and has a better rationale than Garfield Minus Garfield, so it's always to my chagrin that Garfield Minus Garfield is better-known. (That "better rationale" being the fact that in the original, Garfield's "speech" is always shown in thought bubbles, so removing those thought bubbles should theoretically how the strip's events would appear to an outside observer/Jon/anyone without access to Garfield's internal monologue.)

Source: I was there. The PhpBB for the old forum seems to be busted, and I don't think the thread is accessible any more.

DC being what it is, this makes a lot of sense. I only showed up on the xkcd forums, which can go from full of cool people to full of assholes at any moment. It's better now some of the particularly bad trolls have left. Criticising the strip is cool. Being an idiot douchebag isn't.

They have a very different feel. GMG actually modifies the text slightly when it refers to garfield by name and is basically the story of a guy going crazy talking to himself. SG just removes the Garfield lines and answers the question "What is Jon's point of view actually like in Garfield?".

This article is awesome, by the way. I was so addicted to dealing with garfield strips programmatically a few years ago. I wanted to work on a library which could analyze the images, reconstruct the layers and extract the text in order to do things such as removing specific characters, lines, randomizing extracting every single Jon/Garfield sprite and constructing animations out of it, etc.

I feel like Garfield is actually a very cool platform for this because there is a lot of data and not a lot of variations (garfield is extremely formulaic). Maybe this inspires someone to work on it.

(PS: Hint: If you are interested in working on it, scraping every garfield strip off the official website is extremely easy)

At least in Silent Garfield Jon is talking to something instead of nothing which leads to hilarious and depressing scenarios.