>>An elderly person asked me to update his Mac OS 9 system to Tiger, but he
>>uses Think Pascal 4, which I don't know at all. Can someone tell me if Think
>>Pascal 4.0 be used without any problems under Tiger? (And if not, what would
>>you suggest? :)) (Upgrading to a newer version may well be an option, if
>>necessary. But given his age I doubt that switching to another development
>>environment is a good idea.)
>
>THINK Pascal is long, long dead.
>
>It might work in Classic, if you can still run Classic on the new machine.

It might also work inside one of the available emulators such as Mini vMac <http://minivmac.sourceforge.net> which is a great Macintosh Plus emulator or Basilisk II <http://www.users.bigpond.com/pear_computers/> which I use on occasion to run the Newton development kit.