The technology industry slowdown actually helped embedded Linux gain market share, because at a time when all expenses were carefully scrutinized, the cost savings offered by Linux were often a deciding factor in the IT buying process. Now with the economic recovery under way, the embedded-Linux market looks to have a robust future.

The defense segment of the embedded-software industry in particular has remained quite healthy, even during the post-Internet doldrums. In the past, it was believed that embedded Linux would have an uphill task penetrating military systems because of their stringent requirements for real-time performance and reliability, and because of the military's track record for using unique, one-of-a-kind solutions. But it seems that the compelling benefits offered by Linux have led the defense industry to start adopting embedded Linux in many of the largest newer technology-driven programs, which could provide a significant growth opportunity for Linux.

The defense industry is going though a major upgrade to its systems as a part of an ambitious transformation program to support network-centric warfare (NCW). Implementing those programs requires large amounts of networked and heavily integrated software systems. A key factor for success is interoperability across a large number of separately developed systems as they are deployed over many years.

The defense industry is also realizing that Linux, as the only effective multi-vendor open standard embedded operating system, provides a solution to many of the problems of existing OS systems, which have proprietary solutions that make it very expensive and time consuming to upgrade to new technologies or provide interoperability with other systems. Linux is widely supported by the latest hardware devices, and there is a growing platform of Linux-based software in addition to a large amount of existing software based on Solaris and other Unix variants that is easily ported to Linux.

Linux is a good fit with the spiral development model, with frequent technology insertions being adopted for new defense programs. Spiral development controls costs while decreasing cycle times for technology insertion by such using features such as open architecture, module interface standards and COTS hardware. Use of spiral development allows cutting-edge technologies to be fielded more swiftly.

With huge amounts of data, both unclassified and classified, accessible to a variety of users over integrated networks, security is a critical requirement for embedded software in defense systems. Systems that simultaneously handle data at different classification levels must meet stringent MLS (multilevel secure) requirement, as defined by Common Criteria Evaluated Assurance Level 7

No operating system has been certified to CC EAL-7. The main challenge is the intermingling of security functionality with the operating system kernel, all running in a privileged mode, and the complexity of modern operating systems. With Linux you have the additional challenge of the open source development methodology, which doesn't lend itself to the common criteria approach for assurance.

At LynuxWorks, we are also working on a MILS (multiple independent levels of security/safety) separation kernel that is designed to meet EAL7 requirements.

Inder Singh, CEO and chairman, LynuxWorks Inc., San Jose, Calif.