SVGO - Tool for optimizing SVG files
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
SVG Cleaner - Generally, SVG files produced by vector editors contain a lot of unused elements and attributes...
LaTeXDraw - LaTeXDraw is a graphical drawing editor for LaTeX.
Vector Artist - Vector art software designed for tablets.
Ipe - Ipe is a drawing editor for creating figures in PDF or (encapsulated) Postscript format.