A search has begun for Isle of Man firms willing to help fund the Family and Mobile libraries - and safeguard the jobs of 16 staff.
Island-based PokerStars came to the rescue in 2012 when both services faced closure after government withdrew funding.
A three-year deal between the online gaming firm and the Manx Educational Foundation has kept the libraries running a charity.
But the arrangement won't continue beyond 2015 - leaving their future once again, in doubt.
The Foundation says funding secured from PokerStars has not only kept the mobile and family libraries open, but allowed both to expand.
Running costs are put at a quarter of a million pounds per year: the deal with PokerStars, since acquired by new owners, will end next year.
The Family Library houses the largest collection of books for young people in the Island and has more than 2000 members.
It is used by 26 schools to help with curriculum projects.
The mobile library visits 90 different places over a two week timetable, taking books to people who otherwise wouldn't have access to them.
Manx Educational Foundation Director Kurt Roosen says there's now a great opportunity for successful Island businesses to become involved in a true success story.
For more information on funding opportunities for the Family and Mobile Libraries contact Kurt Roosen at kurt.roosen@mef.imClip 1