compression - Is there a built-in zip library in .NET 3.5?

Question

Is there a built-in zip library in .NET 3.5?

If not, what are the popular open source .net zip libraries.

Answer 1

EDIT: See note in comments - SharpZipLib is now unmaintained, and you probably want to avoid it.

Open source: #ZipLib

I believe that the classes in the System.IO.Compression namespace are fine for compressing/decompressing a single stream of data, but there's nothing built into the framework to cope with actual zip files.

EDIT: As noted in Ants' answer, there's System.IO.Packaging.ZipPackage but it certainly looks like that's really designed for use in WPF, and wouldn't be terribly convenient to use for general zip file handling. Worth looking into though. I wasn't aware of it before though... definitely worth investigating.