lhs2TeX is a literate programming tool. It is implemented as a preprocessor that generates LaTeX code from literate Haskell sources. It allows for and provides different styles for the formatting of code. You can easily select between representing operators with mathematical symbols or with ASCII approximations, as well as deciding whether or not to highlight keywords. The formatting of your own defined tokens may be adjusted. Preprocessor-style conditionals are supported, and Haskell can be used to generate parts of the document.
Asymptote is a powerful descriptive 2D and 3D vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. It provides for figures the same high-quality level of typesetting that LaTeX does for scientific text. Asymptote is a programming language as opposed to just a graphics program. It can exploit the best features of script (command-driven) and graphical user interface (GUI) methods. High-level graphics commands are implemented in the language itself, allowing them to be easily tailored to specific applications.
fig2ps is a script for converting xfig files to PS or PDF, processing text using LaTeX. It is intended to help typeset good quality documents, where the font on the pictures is exactly the same as the font in the text. The advantage it has over some other xfig exporters such as eepic is that you compile the picture only once and not every time you compile your LaTeX file, giving a great gain in speed with complex pictures. It should work with LyX.
sMArTH is an equation editor built on open Web standards. The editor itself uses a SVG interface and the application logic is implemented in ECMAScript using the DOM. Both MathML and LaTeX are supported as exporting formats in addition to the SVG format. The most important mathematical content from both LaTeX and MathML is already provided, and this should cover the need of the majority of users. The graphical user interface allows even the most complex equations to be built with simple "Point and Click" techniques instead of writing convoluted typesetting code.
OOoLatexEquation is an OpenOffice.org macro designed to manipulate LaTeX equations. It allows you to create equations and insert them into OOWriter and OOImpress documents as PNG, EPS, and EMF images, while the LateX characteristics are saved in the image attributes. The equations are created with and can be edited through an intuitive GUI. OOoLatexEquation supports an inline mode as in TexPoint which expand simple latex code into appropriate characters using specific TrueType fonts.
The TeXlipse plugin adds LaTeX editing support to the Eclipse IDE. It provides both LaTeX and BibTeX editors, a project creation wizard, and a complete user manual of the editor functions. Additional features include syntax highlighting, document outline, section folding, command completion, cite and ref completion, templates, builder integration, viewer integration with inverse search, and more. The plugin makes it possible for LaTeX documents to be edited and built like normal projects in an IDE, and the viewer support makes it easy to check the outcome.