Experimental overview of transversity

The transversity PDF  can be accessed in semi-inclusive DIS measurements with transversely polarized targets.
The main source of information on  transversity is provided at present from two observables: the Collins asymmetry and the two-hadron asymmetry.
The interpretation of the SIDIS results and the extraction of transversity require external information on the fragmentation function (FF) involved in the processes,
namely the Collins FF for the Collins asymmetry, and the dihadron FF in the two-hadron asymmetry.  Information on these FF  can be achieved in inclusive hadron production in e+e- annihilation.
In this contribution, an overview of the SIDIS results  from  HERMES, COMPASS and JLab experiments is given. The recent results from Belle and BaBar on the FF will be also discussed.