Last modified: 2007-09-13 19:36:26 UTC
See <http://commons.wikimedia.org/w/api.php?action=query&prop=revisions&titles=Main%20Page&format=jsonfm&rvprop=content>. The < was not escaped.
Does JSON *need* to escape <'s then? As far as I can see, it doesn't conflict with anything... Although I admit it looks slightly worse in fancy markup, but bots'll never notice that ;)
This is a problem with fancy html rendering, not with the formatter. Even though it is a bug, it only affects the developers looking at the api call results, not the programs using the api. I will set it to the lowest priority for now.
Fixed on trunk in r25742
Fix reverted in r25832.
Whoops, wrong bug. Sorry.