Interesting Fact about WINDOWS MLOCs
Windows internals is
Probably the best source of information on the Windows Internals 6th Edition
books (two volumes).
Here are some tidbits about the size of the Windows codebase (lines of code
are approximate and unofficial, but based on reasonably credible sources):
| # | Launch Year | Windows Version | Million Lines of Source Code |
|---|---|---|---|
| 1. | 1993 | Windows NT 3.1 | 5.6 MLOCs |
| 2. | 1994 | Windows NT 3.5 | 8.4 MLOCs |
| 3. | 1995 | Windows NT 3.51 | 10.2 MLOCs |
| 4. | 1996 | Windows NT 4.0 | 16 MLOCs |
| 5. | 2000 | Windows 2000 | 29 MLOCs |
| 6. | 2001 | Windows XP | 35 MLOCs |
| 7. | 2007 | Windows Vista | 45 MLOCs |
| 8. | 2009 | Windows 7 | 42 MLOCs |
| 9. | 2012 | Windows 8 | 50 MLOCs |
| 10. | 2015 | Windows 10 | 55 MLOCs |
[Note: There is debate over the methods used to count lines of code, but if you use the same criteria from one release to the next, you can see the relative change in the size of the codebase. Comparing these numbers with those of another OS that used a different method of counting lines of code is like comparing apples to oranges.]
| Codebase | |
|---|---|
| 🗔 | Windows source code consists primarily of C, C++, and a small amount of assembly language code. |
| 🗔 | I didn’t include the 16-bit-esque versions of Windows. NT was the basis for all modern 32-bit and 64-bit versions of Windows. The number of lines of code in server versions was the same as the non-server versions released in the same year (i.e., they had the same source code base). |
| 🗔 | Work on the NT kernel began in 1988, written from scratch as a 32-bit OS. The NT kernel first booted in July 1989 on an Intel i860 RISC processor. There was a strong push from the outset to ensure that the new OS was portable to a variety of CPU architectures, and wouldn’t be locked into only the Intel x86 (IA-32) architecture. NT was eventually running on MIPS, DEC Alpha, PowerPC, Itanium, and of course Intel x86 and x64. |
| 🗔 | MLOC. Millions of Lines Of Code. |
