The trio started for Munster in their recent British & Irish Cup semi-final win over Ulster Ravens. Scrum half Williams scored a try in that game, which came a week after loosehead Ryan's first start for Munster against Connacht in the Magners League.
Academy players Ian Nagle, Dave Foley, Stephen Archer, Scott Deasy, Peter O'Mahony and Danny Barnes have been promoted to full development contracts with Munster.
Of the lot, the versatile Deasy has made the most headway this season with the province's senior squad. The 22-year-old impressed with a 14-point haul in February's Magners League win over Edinburgh and made his Heineken Cup debut last weekend against Biarritz Olympique.
Nagle and Foley are two very promising second rows, while back rower O'Mahony has starred for Cork Constitution in the AIB League and AIB Cup and captained Munster through to next week's British & Irish Cup final.
Training-contracted player Declan Cusack, Munster's top scorer in the British & Irish Cup, has also been impressing the province's management. The Thomond out-half has been bumped up to a full development contract.
Meanwhile, Munster have confirmed that Worcester Warriors centre Sam Tuitupou will join them - subject to the usual medical and fitness examinations - at the start of the next season along with Leicester Tigers and Ireland Wolfhounds winger Johne Murphy.
Born in Auckland, Tuitupou played nine times for the All Blacks between 2004 and 2006, including four starts against Argentina (2) and South Africa (2).
He is a former New Zealand Under-19 and Under-21 captain, winning World Championship titles at both age grades, and was a regular for Auckland Blues in the Super 14 before moving to English side Worcester in 2007.
A dynamic and tough tackling midfielder, the 28-year-old played 54 times for the Warriors, scoring 13 tries during his three-year stint at Sixways Stadium.