Extensive High Availability Modules is a light weight failsafe system that could be integrated with legacy opensource products such as Sendmail, Qmail, Apache, MySQL, VSftp, WUftp, Bind, Samba, NFS, IPTables, etc. In addition, XHAM can also be customized to work with stateless proprietary applications.

For people, who don't like long project name, please refer to this project as a Failsafe project.

Actually, I have started developing this kind of software since 2001 when I was extremely disappointed with an expensive Commercial-Off-The-Shelf (COTS) Failsfe software. I found that many generic failsafe systems in the market have the some annoying deflects such as Hardware Dependence, Using Buggy Ping as heartbeat, Bing & Clumsy GUI Process, and almost impossible to be modified.

First, I spent my own leisure time developing its prototype at home. After that my failsafe was shown to the public for the first time when we need to demo High Availability proof-of-concept to our potential customer but that underlying expensive COTS Failsafe software kept failing. I therefore replaced that buggy failsafe with mine, and "BINGO", it did work very well and we all survive from the demonstration.

The feedback from customer was very good and it had raised a fear on me that my previous company would take the ownership on my own personal work. Thus the best way out is to release this product to the world as an Open Source one.

My previous project wasn't called XHAM but LHAM. Unfortunately, it wasn't so successful as it was too difficult for the end user and ordinary system administrator. I therefore re-build my project with an intention to make it as easy for use as possible. Thus, XHAM is divided into serveral applications (all applications are derived from the same fundamental modules) such as Twoway-Single-Master-Single-Slave, Gateway-Failsafe, Twoway-With-Two-NICs, etc.

I hope, you will enjoy using this software. In addition, you are always welcome should you want to contribute to this project.

By the way, I would also like to thank International Effiscient Co Ltd for their contribution in term of testing facility, funding, ocumentation, and valuable advice. Please see www.ieffiscient.com for more information about them.