David Elson, A member of the Sydney PHP users group and managing director of consulting firm Babel.com, said there has been a fair amount of interest in Mono from the open source community and the .Net ecosystem now has a "good number" of core developers, as the project has started to develop some stability.

Whether Mono will realize its potential as a mainstream, cross-platform development environment will depend, Elson said, on the set of developers committed to developing code with it.

"What I'm seeing is that the uptake of Mono as a cross-platform development environment hasn't yet reached critical mass on Linux," he said. "Basically, if a developer wants to write an application to run on multiple platforms, the developer has to either port the application multiple times, write it using a cross-platform kit such as Mono or Java, or make the application Web-based so that it can run anywhere, in any Web browser, which is becoming the "platform" of choice for many developers."

It is this trend towards Web applications that Elson believes may eclipse interest in both Java and .Net, even though applications developed with both of those environments can be delivered via a Web browser.

"At the Web server back-end, although Mono applications can be deployed with some success, the primary, large-scale platform still appears to be J2EE," he said. "The LAMP stack is gaining in ground in the mid-scale area, and the uptake of cross-platform scripting languages such as PHP and Perl has engendered Python and also some others. Toolkits like Zope have also established their own particular corner of that market and are unlikely to be supplanted by Mono."

On the desktop, Elson said there are an increasing number of cross-platform applications being developed and deployed with Java, and there doesn't appear to be room in that marketplace for Mono. Particularly when the largest number of applications are still being coded in native languages such as C and C++, and ported to each platform, Elson said.

"That doesn't [mean] Mono doesn't have the credentials, it just appears to have hit the market at a less than ideal time," he said. "There will, of course, be specific applications developed in Mono-C# both now and over time for various reasons, but it's not going to gain a significantly large share of the market nor is it going to drive the other development platforms underground."

That said, Elson believes Mono has great potential on the desktop, but that it remains to be seen whether it will ever be "lifted to that potential".

"Part of this is the natural resistance to change," he said. "Programmers, like the rest of us, dislike having to learn a new language."

While Mono and Java are technically comparable, Elson said there are significantly fewer toolkits available for Mono than Java, and Java application Web sites like JPackage don't really have a comparable parallel in the Mono world.

Elson cites insufficient critical market mass to drive the adoption of Mono, and that is its major shortcoming.