The apple apps on my imac have crashed.?

I loaded my mac up yesterday and when I tried opening any apple software such as safari, pages, mail etc they just bounced once in the dock and then did nothing. The problem is occurring on all profiles on the mac. I have an inkling that it could have been caused by the fact that I opened iphoto before I turned the system off and clicked to repair the library at which I had to force quit the program as it was not responding. Does anyone have any idea how to fix this problem? All the other programs are working fine that aren't made by apple: such as firefox. My operating system is Mac OS X version 10.6.8. Thanks.