Keri Systems, www.kerisys.com, produces a very cost effective access control system.  Keri's door controllers can control one or two doors per controller the system can be expanded to control hundreds of doors.  Keri is a price leader in the access control system industry. 

Keri produces their own proximity readers that are cost effective as well as accepts other weigand compatible readers.

Keri offers their software at no charge, as a part of their system.  This windows based software is very easy to use and will run on a Windows 95, 98,  NT4, 2K and XP Pro platforms. 

Keri is ideal for small organizations that want to have access control at a reasonable price and are not concerned with some of the more sophisticated features that are offered by other systems.