well, that's an outlook feature and hence outlook has to support it. You don't need any other special software.
I've used it a while back with Kontact. Basically the PIM Software (Kontact, Outlook) will create additional folders on the imap/pop account into which it then stores, retrieves, updates, deletes calendar and tasks entries. All you need to have is the ability to create folder in your imap account. Everythinig else is handled by the PIM Software - at least that's how I understand on how it works.
"Common sense is not as common as commonly believed" by sjau