ReactOS was started somehow in 1996 (and still in alpha?), Haiku-OS is in beta 5 (initial release was in 2002 per Wikipedia) and Microsoft required years for creating Chicago/Windows 95 or Longhorn/Vista

How many years do you need to create own OS? Is it even possible?

Project goes further (see GitHub repo). But why it could interesting for anybody?

My Linux story started long before 2000 year in totally other time - internet was something new and not very available (for me) and distributions were normally provided on the CD (additionally configuring hardware and things like X-Windows was really something and sometimes I was using even floppy disks for some tasks like booting system). Ca. 2000 I was already writing some universal software working in Windows AND Linux (mainly with serial cable, infrared or bluetooth connections, but of course not only).

Some standards were created and market was growing. Later it was only better and more optimistic - Mandrake, Mandrive, RedHat, Debian, Ubuntu and many others were always adding something.