Puppy Linux
Puppy Linux-tan was first drawn by an artist known as Bella. Puppy Linux-tan is the personification of Puppy Linux, a small, lightweight distro, most often run entirely off of a computer's RAM; Via LiveCD, USB drive, etc.
Puppy Linux-tan is depicted as a blonde haired, brown eyed dog-girl of small stature. She's of a young age, both as a reference to the distro's name (puppy) and as the distro's unusually small size.
Her attitude is spirited and energetic (due to her young age, and as an injoke referring to Puppy Linux's speed). She enjoys playing with other dog-girls (both Linux and otherwise) and sometimes chases cat-girls, though always in good fun. She's also a bit tomboyish, not one for frills or fancy dresses. Sometimes, though, she will wear a Windows 98-tan-like schoolgirl outfit. Both are references to Puppy Linux's somewhat utilitarian, and Windows 95/98-like GUI.