wyUpdate is the open source updater that's included with wyBuild. wyUpdate checks for updates, downloads any that are available, and safely updates your program. It handles in stride obstacles like Windows Vista / Windows 7 / Windows 8 User Account Control (UAC), limited-user problems, and many other subtleties. wyUpdate can patch files using the VCDIFF delta-patch format. It also can handle errors, and rollback updates if there is unrecoverable error. wyUpdate is written in C# and is licensed under the BSD License.