LibreOffice - Math - Math, LibreOffice, math editor, ODF, OpenFormula, open standards
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.
Math Magic - MathMagic Equation Editor for Desktop Publishing software & Word Processors, Adobe InDesign, QuarkXPress, MS Word, iWork, for Technical writing with very easy interface and fast input.
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.
KLatexFormula - KLatexFormula is an easy-to-use graphical application for generating images (that you can drag and...
Wondershare PDFelement - All-in-one PDF editor