Below is the snippet that I read about IOS software. Is there personally any reason why you stick solely with Cisco?
Cisco IOS Software: The Future
The strategy for the Cisco IOS software is to continue to provide technologies and solutions based on customer needs. Cisco IOS software will continue to drive industry standards as well as expand to all strategic internetworking platforms.
A growing number of leading network and computer vendors are integrating Cisco IOS software capabilities into a range of internetworking platforms, such as servers, hubs, WAN switches, remote access devices, multiplexers, and PBXs. The goal of this strategy is to ensure users receive industry-leading technologies and high-quality networking software. Cisco IOS technology licensing delivers these services in the form users require, whether or not Cisco manufactures the hardware. Companies leveraging the Cisco IOS software technology in LAN-based products include: Bay Networks, Chipcom (3Com), Cabletron, Digital Equipment Corp., LanOptics, Lannet, and Optical Data Systems. Companies leveraging the Cisco IOS software technology in WAN-based products include; Alcatel, Ericsson, GTE Government Systems, Northern Telecom, and US Robotics.
Other companies have Cisco IOS software-based products in development, including Compaq, Hewlett-Packard, NEC, and Ungermann-Bass. It's all part of Cisco's drive toward multivendor, multiplatform network interoperability. Customers can now choose from many different vendors and platforms and still be assured they are receiving all of the benefits that the Cisco IOS software provides.