ClamWin is a free antivirus software based on the ClamAV engine with a GNU General Public License given by the Free Software Foundation. It is built to run on Windows Vista, Windows 7, Windows XP, Windows Me, Windows Me, Windows 2000, Windows 98, Windows Server 2003 and Windows Server 2008. It features a scanning scheduler, and it automatically downloads updated virus database regularly. It has a stand alone scanner and a right click menu that is integrated to the Microsoft Windows Explorer. It works as an add-on in Microsoft Outlook which monitors e-mail attachments and removes virus infected attachments immediately. Its has detects viruses and spyware, but does not include an on-access and real-time scanner. Users will have to manually scan a file to detect virus or spyware. ClamWin can not automatically scan files as they are read and written. Developers plan to include this feature into the next major version update and is said to be in development since December of 2005. An affiliated project, the Clam Sentinel, serves as an add-on that can proved real-time scanning capabilities to ClamWin.