OS-9
A realtime, UNIX-like OS from Microware Systems Corporation. OS-9 is commonly an embedded OS used in portable devices but is mainly used in the Interactive TV Set Top Box market.
OS-9-tan is a hotshot TV idol but wallows in obscurity. She is brave but also very rash and does not think twice before doing or saying something- most infamous example is when she openly talked bad about Unix, reference Unix's mentioning in the OS-9 manual:
UNIX: An operating system similar to OS-9, but with less functionality and special features designed to soak up excess memory, disk space and CPU time on large, expensive computers.
Ironically, OS-9-tan wants to be a lot like Unix but hates her at the same time.
OS-9-tan has dark purple-blue hair and light blue eyes, dons a purple sleeveless shirt with a gray bowtie, separate white collar, long white gloves, blue + orange skirt with OS-9 on the side, long blue socks and dark blue ballet flats. She also has an intentional resemblance to Mac OS 9-tan because there have been several people that confused OS-9 with Mac OS 9. It is not uncommon for the two OS-tans to get their mail and packages mixed up by clueless messengers, or for the Mac OSX-kuns to swoon over her because they thought she was Mac OS 9-tan with purple hair!
She and CoCo-tan are close friends because OS-9 is one of the commonly used OSes on the CoCo. She is also friends with Amiga-tan although Amiga-tan is often much too busy and also has a dangerous fangirl [DragonflyBSD-tan] that OS-9-tan is too scared to approach. Also, OS-9-tan's and CoCo-tan's friendship is deemed a forbidden friendship by their clashing userbases.
She is also in a three-way rivalry with QNX-tan and Windows CE-tan who are main competitors in the embedded OS market.