News for ikiwiki 2.62:

The teximg plugin now has a configurable LaTeX preamble.

As part of this change the mchem LaTeX package has been removed from the default LaTeX preamble as it wasn't included in many TeX installations. The previous behaviour can be restored by adding the following to your ikiwiki setup:

 teximg_prefix => '\documentclass{scrartcl}
         \usepackage[version=3]{mhchem}
         \usepackage{amsmath}
         \usepackage{amsfonts}
         \usepackage{amssymb}
         \pagestyle{empty}
         \begin{document}',

In addition, the rendering mechanism has been changed to use dvipng by default, if available.

ikiwiki 2.62 released with these changes