End users with little software background are developing numerous software applications using devices such as spreadsheets, web mashups, and web macros. Web mashups are particularly popular because they are easy to create and there are large public repositories that store them and allow their reuse. Existing repositories, however, provide no functionality for tracking the development histories of mashups. We believe that versioning capabilities can help end users develop, understand, and reuse mashups. To investigate this belief, we created a versioning extension for Yahoo! Pipes -- a popular mashup environment -- and conducted an exploratory study of users utilizing the environment. Our results show that versioning information allows users to perform mashup creation tasks more correctly and in less time than users not having that information, while also improving the reusability of pipes.