Complex sentence: The first CPU to use this architecture was the "Willamette" core, released in November 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst.
Split into simpler sentences: The first CPU to use this architecture was the "Willamette" core, released in November 2000. This was the first of the Pentium 4 CPUs, and all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst.