I really like WoltLab, they have a great Forum and the community is generally really nice The customer support is also awesome
Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
phpBB - Raspberry Pi. The Raspberry Pi is a cheap, credit-card sized computer. The official website uses phpBB for their discussion forums. phpBB is not affiliated with nor responsible for any of the sites listed on the showcase.
Wondershare PDFelement - All-in-one PDF editor
Flarum - Flarum is the next-generation forum software that makes online discussion fun. It's simple, fast, and free.
Microsoft Word - Microsoft Word is a commercial word document processor for Windows.