Simon Thorneycroft and Jonathan Hodgson

How many lines of code?

Really interesting statistics on the size of Visual Studio 2005 by Mike Stall.

Visual Studio is over 43 million lines of code, there are over 30 teams working on different pieces, with roughly 700 developers checking-in code to 11 different virtual build labs that are then integrated on a rotating schedule producing over 100 different builds of the product daily.

Between that and Windows source code, Microsoft really is building software on a totally different scale to nearly every company.

We've had a very interesting challenge scaling development and testing techniques up to a product of that size. It seems like most methodologies ("You just write unit tests for everything and then you have no bugs") I hear about are really intended for about 5 person teams. If you had a unit test for every 10 lines of code, that's 4 million unit tests. That's would be a lot of unit tests to run before a single check-in.

Also Scott Guthrie talks about the automated testing that goes into ASP.NET which gives another great insight.

It really is a engineering on a different level, especially how Microsoft manages all this development at the same time as issuing hotfixes across all the different product lines.

It's great some of these practises and what Microsoft have learnt are being shared with the outside community.