Printer port confusion

Is there a reason why different websites list different
signal states on some parallel port pins? Are some just
wrong, or were there two types of parallel ports for
PC's at one time?

For example:
http://et.nmsu.edu/~etti/fall96/computer/printer/printer.html
indicates that pins 10 and 15 are inverted inputs, while

http://ourworld.compuserve.com/homepages/Bill_Bowden/page6.htm#p_input
has 10 and 15 as _normal_ inputs while *11* is inverted!

I just found out my PC has the latter pinout, while I
had wired a ciruit assuming that the first website (and
another that agreed with it) were correct.

<grumble>

I just want to know if I'm going to have problems with
pinouts if I want to hook a microcontroller to different
PC's and their parallel ports.
.