How is open source affecting software development?

The way proliferation and availability of open source is affecting software development efforts are discussed. From a developer's perspective, open source is a combination of visible source code and a right to make unencumbered derivatives. The open source community gives a rich base of reusable software, typically available at the cost of downloading the code from the Internet. A problem associated with reusing open source elements is that their quality varies widely from shoddy to industrial strength and no standardized processes and metrics exist for assessing the quality of a given element.