.NET 4.5 or newer finally has built-in capability to handle generic zip files with the System.IO.Compression.ZipArchive
class (http://msdn.microsoft.com/en-us/library/system.io.compression.ziparchive%28v=vs.110%29.aspx) in assembly System.IO.Compression. No need for any 3rd party library.
string zipPath = @"c:\example\start.zip";
using (ZipArchive archive = ZipFile.OpenRead(zipPath))
{
foreach (ZipArchiveEntry entry in archive.Entries)
{
Console.WriteLine(entry.FullName);
}
}