What is open source software? Krish Advani 13/06/2013 Engineering Open source software are those, whose code is available to be modified, without having any restrictions. These software are normally free of cost and the code can be edited by any user or developer to fit his/her needs. The developers or users can improve, perform test, experiment with the software in any possible way imaginable. Software which are oper source have a certification mark owned by the Open Source Initiative. No ristrictions must be present while redistrubitudig the software and the source code must be available.