Feng Office - Feng Office is a commercial Open Source web based solution aimed to enhance collaboration and productivity
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
Magic Spreadsheet - Human workforce and AI plugged into your Google Spreadsheets
Redmine - Flexible project management web application
Sheetsu - Turn Google Spreadsheet into API