Linux was started in 1991. Windows NT (whence Windows XP and modern Windows versions derive from) dates from at least 1993 (I don't know when the code internally started, but the first release was 1993).
For browsers, Firefox source code originates from Netscape 6, which was a rewrite from scratch and shared little to no code with Netscape 4 or earlier. This rewrite happened in 1998. IE dates from 1994, per Wikipedia. KHTML, whence Safari and Chrome ultimately derive, is itself from 2000.
Let's talk about programming languages. Java dates its early work to 1991. .NET Framework is the late 90s (Wikipedia is exceptionally poor with dates here). The LLVM framework dates to 2000 in the earliest. Accelerator programming languages like CUDA and OpenCL are deep into the 2000s in their genesis, and the development of more fully heterogeneous programming languages obviously postdates that.
That's a lot of significant projects that date way later than Linux.