Microsoft is to converge features of Visual Basic and C# languages with their planned upgrades to the two platforms, according to a senior company executive.

Visual Basic 10 and C# 4 are both due concurrently with the Visual Studio 2010 IDE, which might ship at the end of the year.

The Visual Basic and C# teams were merged into one team last year; it's called the Visual Studio managed languages team," said Beth Massi, senior program manager at Microsoft, during the VSLive conference in San Francisco. Also under the team's domain are the F# language, for functional programming, and Microsoft's DLR (Dynamic Language Runtime), supporting dynamic languages on the .Net platform.

Visual Basic and C# developers build the same type of applications, such as web and business applications, and the intention is to co-evolve the languages together, Massi said. .Net has unified how applications are written, she said. "It's much less focused on the language," Massi said

Visual Basic 10 and C# 4 will gain interoperability with dynamic languages. Programmers, for example, could tap into a JavaScript engine in an ASP.Net application, according to Massi. "In both of the languages, Visual Basic and C# are going to have interop with the DLR," for interaction with scripting languages such as Python, Massi said. The DLR has not yet been released.

Both Visual Basic 10 and C# 4 also are to get an array literals capability for inferring array types. The two languages also will gain collection initialisers for initializing a list or dictionary with data using the new "from" keyword.

Multi-line and statement lambdas, another ease-of-use feature saving programmers from having to return values, also is due in both language upgrades. Compiling without primary interop assemblies also will be enabled in both.

A generic variance capability will be offered in the languages for widening or narrowing the scope of generic types, such as a list.

Visual Basic 10 also will include auto-implemented properties, an ease of use programming feature already in C# 3. Also, Visual Basic 10 will gain an implicit line continuation capability so developers do not have to write underscores in LINQ (Language Integrated Query).