Computerworld is undertaking a series of investigations into the most widely-used programming languages. Previously we have spoken to Alfred v. Aho of AWK fame, S. Tucker Taft on the Ada 1995 and 2005 revisions, Microsoft about its server-side script engine ASP, Chet Ramey about his experiences maintaining Bash, Bjarne Stroustrup of C++ fame, and Charles H. Moore about the design and development of Forth.
In this interview Microsoft's leader of C# development, Anders Hejlsberg, took some time to tell Computerworld about the development of C#, his thoughts on future programming trends, and his experiences putting out fires. Hejlsberg is also responsible for writing the Turbo Pascal system, and was the lead architect on the team that developed Delphi.
(Please note that due to popular demand we are no longer following alphabetical order for this series. If you wish to submit any suggestions for programming languages or language authors you would like to see covered, please email firstname.lastname@example.org.)
What were the fundamental flaws in other languages that you believe drove the development of Common Language Runtime (CLR), and in turn, C#?
I wouldn’t say that our primary motivation for CLR was fundamental flaws in other languages. But we certainly had some key goals in mind. Primarily, we wanted to build a unified and modern development platform for multiple programming languages and application models.
To put this aim in context, we need to look back to the inception of .NET, which was in the late nineties or early 2000s. At that time, Microsoft’s primary developer offerings were fairly fragmented. For native code we had C++ with MFC, and ATL and so forth. And then for rapid application development we had Visual Basic, and for web development we had IIS and ASP.
Each language was its own little silo with different solutions to all of the different programming problems. You couldn’t transfer your skills and your application model implicitly became your choice of programming language. We really wanted to unify these separate entities to better leverage our efforts.
We also wanted to introduce modern concepts, such as object orientation, type safety, garbage collection and structured exception handling directly into the platform. At the time, the underlying infrastructure we were running on was COM, which is a very low level programming model that requires you to deal with the registry and reference counting and HRESULTs and all that stuff.
These factors were, at the time, the motivators for .NET. There was also a competitive angle with Sun and Java etc.
Now, to move on to C#, in a nutshell our aim was to create a first class modern language on this platform that would appeal to the curly braces crowd: the C++ programmers of the world at the time, and competitively, the Java programmers.
There were several elements that we considered key design goals, like support for the next level up from object oriented programming, to component based programming where properties and metadata attributes were all first class in the language. Also, a unified and extensible type system, which sort of gets into value types and boxing etc. Versioning was a big thing; making sure we designed the language so that it would version well, so that whenever we added new features to the language we would not break code in older applications. These were all values that were important to us.
Of course, at the end of the day, productivity has always been a driver for me in all of the projects I’ve worked on. It’s about making programmers more productive.