Alia Systems Limited
- UK company performing bespoke software development for IBM mainframes, AS400, and UNIX systems. Also integrates legacy systems with emerging technologies.
- http://www.stateframe.com/

HOB, Inc.
- Offers development to facilitate mainframe connectivity and encryption.
- http://www.hobsoft.com/

IT Doctors
- Association of UK-based mainframe consultants. Highlights platforms and languages supported.
- http://www.itdoctors.co.uk/

Maintec Technologies
- Offers training and development services.
- http://www.maintec.com/

H&W Computer Systems, Inc.
- Develops system and application software for mainframes and PCs. Information about products and support.
- http://www.hwcs.com/

Mainframe Software Innovations
- Application performance improvement specialists that reduce run-time and CPU-time of application programs in an IBM mainframe environment.
- http://msinow.com/

Innovative Software Solutions
- Develops and maintains applications for the AS/400 platform. Also migrates and ports existing software and data.
- http://www.webpgmr.com/

ResQNet
- Develops graphical Java connectivity products that web-enable Mainframe and AS/400 systems and automatically present their screens as GUIs.
- http://www.resqnet.com/