OpenOffice has been improved and given a new name. It's been renamed LibreOffice loads faster and so on. I loaded a pdf file and could edit the pdf file. It can make pdf files too.
I agree OpenOffice or LibreOffice are equal to Microsoft Office. Most people never use more than 1/1000 of the power of any of the office suites. Most of the suites are similar enough that the learning curve for changing is minimal.
You don't have to worry about quality or compatibility. OpenOffice and LibreOffice have been developed over the years by dedicated volunteers and supported by the likes of Sun Microsystems and Oracle. This is an international effort using the power of the Internet.