Celebrant (obviously the bishop) in chasuble
Deacon in dalmatic
Subdeacon in tunicle
Assistant (also called Arch-) Priest in cope
Deacon of the Throne 1 in cassock, surplice and dalmatic
Deacon of the Throne 2 in cassock, surplice and dalmatic
The above are the only ones who must be in holy orders, but there are usually more.
Master of Ceremonies #1 does his usual role in cassock and surplice (preferably a priest when it is a Pontifical Mass)
Master of Ceremonies #2 handles the pontifical movements to and from the throne, etc., in cassock and surplice (preferably a priest)
Four servers, holding pontifical candle, book, crozier and mitre. The latter two also wear the vimpas. All wear cassocks and surplices. I have seen in one place, these wearing simple copes, as well, but this is not in the rubrics, as these servers are nearly always lay, often younger servers.
Then there are the thurifer, AC1. AC2, crucifer (in tunicle, if he is a subdeacon) and eight torchbearers, rather than six, because of the Pontifical Mass. All wear cassock and surplice.
