Mark Pilgrim summarizes his research into RSS compatibility:
“There are 9 versions of RSS, all of which are incompatible with various other versions. RSS 0.90 is incompatible with Netscapeís RSS 0.91, Netscapeís RSS 0.91 is incompatible with Userlandís RSS 0.91, Netscapeís RSS 0.91 is incompatible with RSS 1.0, Userlandís RSS 0.91 is incompatible with RSS 0.92, [...]
