when myspace first started, they were using coldfusion. they switched to blue dragon and asp.net servers in early 2006, but they're still using coldfusion on the browse pages, i believe. the switch ended up cutting server usage in half, so i doubt they'll ever switch back. they just kept the .cfm extension to keep links intact.
an
article by scott guthrie, with comments by myspace's developers.
unfortunately, you won't be able to use coldfusion, php, or any special languages. the only ones allowed are CSS, HTML & embedded flash (provided links are HTML).