Vendors like Anant, Biblibre, ByWater, Calyx, Catalyst, inLibro, IndServe, Katipo, KohaAloha, LibLime, LibSoul, NCHC, OSSLabs, PakLAG, PTFS, Sabinet, Strategic Data, Tamil and Turo Technology take the code and sell support around the product, develop add-ons and enhancements for their clients and then contribute these back to the project under the terms of the GPL license.