How has the open source development process influenced software development in general?

Open source development software is developed collaboratively; source code is freely available for use and modification. The open source movement arose because some developers came to believe that competition amongst vendors’ leads to inferior products and that the best approach to development is a collaborative one.

The OSI (Open Source Initiative) is an industry body that certifies products as open source if they conform to a number of rules:

The software being distributed must be redistributed to anyone else without any restriction

The source code must be made available (so that the receiving party will be able to improve or modify it)

The license can require improved versions of the software to carry a different name or version from the original software

Despite its emphasis on the collaborative process, the biggest influence that open source has had on software development in general may be through competition: by competing with proprietary software products, open source products force vendors to work that much harder to hold their market share in the face of viable open source alternatives.