LDraw - LDraw is an open standard for LEGO CAD programs that allow the user to create virtual LEGO models...
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
LDCad - LDCad is a multiplatform ...
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.
LeoCAD - LeoCAD is a CAD program for creating virtual LEGO models.
Wondershare PDFelement - All-in-one PDF editor