Open Office is a great replacement for all microsoft ‘office’ apps. Why rent, when you can get it for free?
Open Office is a bit of a joke. They haven't made any real improvements to it for years.
Several years ago, a group forked off of Open Office to form Libre Office. It has been continuously improved, and is much more feature rich than OpenOffice now.
I strongly recommend Libre Office to those who want a FOSS office suite.