In a recent exploration of the domain, textik.com is rather bare bones, but does have some interesting features. In particular, it recognizes certain spots on

In a recent exploration of the domain, textik.com is rather bare bones, but does have some interesting features. In particular, it recognizes certain spots on the border of a rectangle as connection points. Drawing a line between two connection points establishes that similar to how drawing programs handle lines - including the "if you drag that rectangle around now, the lines connected to the connection points adjust too."