The present invention provides curable compositions that are free of metal catalysts including both tin and non-tin metal catalysts. The curable compositions employ a catalyst comprising curable polymers having reactive terminal silyl groups. In particular, a silylated carboxylic acid is an alternative to organotin or other metal catalysts. In addition, the catalyst may be used with an amino-containing adhesion promoter or a mixture of amine-containing adhesion promoters and an amino-containing siloxane. The combination of these materials accelerates the condensation curing of moisture curable silicones/non-silicones even in the absence of a metal-based catalyst.