The calc() function is part of the CSS3 /Values & Units/ module[1] which is currently in Last Call status[2]. Here[3] are the status definitions that apply to CSS3. It doesn't make sense to remove the moz prefix until the standard is (probably) done changing.
In addition, mozilla's implementation of it is still in flux (since it's not done) and using the non-extension terminology for an in-development feature is a great way to convince people to use it and then screw them over when you change it.
Also, I found out about all this because you asked. So thanks for causing me to learn something new today :)
In addition, mozilla's implementation of it is still in flux (since it's not done) and using the non-extension terminology for an in-development feature is a great way to convince people to use it and then screw them over when you change it.
Also, I found out about all this because you asked. So thanks for causing me to learn something new today :)
1) http://www.w3.org/TR/css3-values/#calc
2) http://www.css3.info/modules/
3) http://www.css3.info/css3-development-status-an-explanation-...