Novell's paid-for MonoTouch SDK is built on open-source Mono for the iPhone, leading to complaints from some free software supporters about the cost.
Novell on Monday introduced MonoTouch 1.0, a development framework for Apple's iPhone and iPod Touch that uses Microsoft's .Net with C# and other programming languages.
The MonoTouch framework, available on paid-subscription only, requires Apple's own software development kit and runs solely on Macintosh hardware.
"The vast majority of Windows-centric developers, ISVs, and IT organizations have chosen the C# language and .Net for development," said Miguel de Icaza, Mono project founder and Developer Platform vice president at Novell, in a statement.
"As such, we have seen tremendous demand for tools to build .Net-based iPhone applications."
MonoTouch supports most .Net functions, with some differences due to the different security model of the iPhone. There is no support currently for Silverlight or Moonlight, the media delivery and scripting functions of .Net.
The iPhone developer license forbids scripting engines or just-in-time (JIT) compilers, which .Net needs to run code.
"As a result, the world of iPhone applications had been previously closed to .Net and Mono developers. Developers can now use MonoTouch while fully complying with these license terms because MonoTouch delivers only native code," Novell said in a statement.
Reaction from developers has been mixed, with many commenting that the Mac-only, paid-for approach is disappointing, given that MonoTouch is built on the cross-platform, open-source Mono.
Zef Hemel, a researcher at the Delft University of Technology, said via Twitter: "I was excited about MonoTouch coming out to develop iPhone apps on Mono, but now that I see the pricing ($399 to $999) I'm not."
MonoTouch costs $399 per year for an individual license, $999 per developer for an enterprise license, or $3,999 for five enterprise licenses. An evaluation version will be made available later this week, de Icaza said.
Rupert Goodwins of ZDNet UK reported from London.