I believe this article will give you exactly what you are looking for:
http://www.4guysfromrolla.com/articles/092910-1.aspx[
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Right now I believe you still have to use that third party library but in .NET 4.5, you can do this without a library because it is built in. I did an article on zip files in .NET 4.5 recently, although I didn't discuss the web side of things. It might be of use to you in your planning, depending on if you want to use the latest version of .NET or not. Here is a link to the article, in case you are interested:
Creating Zip Files Easily in .NET 4.5[
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