OpenOffice is a free office suite of tools to install on your desktop to create documents, spreadsheets and presentations. It is compatible with MS Office.
Cost: Free. Open source
Availability: Download

Past Overall Rankings
2018: –      2017: –     2016: –      2015: –     2014: 82   2013: 98
2012: 87   2011: 61   2010: 61   2009: 71   2008: 41   2007: 31

Comments from some of those who selected OpenOffice as one of their Top 10 Tools 

“Free, easy to customise, styles are a great way to create coherent looking documents” Chris Kirkland, 2014

Pre-2013 comments

“The open source office suite which helps me redacting reports and papers as well as creating presentations, graphs and so on.” Guy Boulet

“A wonderful office suite that has seen a lot of growth and improvement since I first started using it.” Robert Chapman

“I’ve been using the free and open source OpenOffice for so long that I don’t remember the other office suites. It saves in multiple formats, including MS .doc, .xls and .ppt, and exports to Flash or PDF with a single click.” Harold Jarche

“The great thing on OpenOffice is that the windows version is exactly the same as the Linux version. It doesn’t matter on which system you are.” Tim Schlotfeldt

“Especially for producing PDF-files from Office-documents.” Wilfred Rubens

“Impress – better than Powerpoint, and exports to Flash” Nick Hood

“Would definitely recommend beginners use Writer instead (of Word)” Michael Chalk

“I have gotten personal thank you notes from students for introducing them to Open!” Susan Quinn