The Ada Resource Association has claimed "a major milestone" in the development of the highly typed programming language widely used in mission critical military systems.

The International Standards Organisation's Ada Working Group (WG 9) has unanimously accepted a proposed amendment to the language and has forwarded it to the parent organisation for an official ballot. Formal approval is expected later this year.

Commonly referred to as Ada 2005, the new amendment to the language is the result of a collaborative international effort to enhance the 1995 version of Ada.

The effort was sponsored in part by the Ada Resource Association, which helped support the work of the project editor Randall Brukardt.

The development includes enhancements that unify the language's concurrency and object-oriented features through a new interface that allows implementation through either a sequential or concurrent type.

Support for safety and security is also enhanced with the inclusion of the Ravenscar Profile, a tasking subset that is amenable to safety certification, syntax that avoids some common object-oriented programming errors with inheritance, and a mechanism for defining language profiles.

Other enhancements increase the language's general expressiveness, for example by allowing nested subprograms to be passed as run-time parameters, and by extending the predefined environment with new functionality, such as a containers library.

"Gaining WG 9 approval for the amendment to the language is a key step," said James Moore, convener of WG 9.

"The new features draw on programming language design and user experience over the past 10 years, and should serve to increase Ada's attractiveness in applications where reliability, safety, efficiency and maintainability are demanded."