Many of the large systems of linear equations can be encountered in science and engineering are derived from the solution of partial differential equations. To this end, a whole range of numerical techniques have been developed in order to solve a linear system.

Zotero [zoh-TAIR-oh] is a free, easy-to-use tool to help you collect, organize, cite and share your research sources. I use it as the standard solution to manage references in my scientific documents written in LaTeX.

For my publications, I'm using Inkscape to create vector graphics in svg format and finally, I convert them to pdf format in order to import them into a LaTeX document.