This image shows the excerpt of a CV produced with the moderncv document class:

Notice that after the bold text there is a comma. This seems to be produced automatically. How can I stop this?
This image shows the excerpt of a CV produced with the moderncv document class:

Notice that after the bold text there is a comma. This seems to be produced automatically. How can I stop this?
The entry you're showing is produce with \cventry, so we want to change the definition of this macro. It is defined in moderncvstyleclassic.sty. All I did is copy it into my preamble verbatim and remove the undesired comma. (In the MWE, I actually copied the line and commented out the original, to make the change recognizable.
\documentclass{moderncv}
\moderncvstyle{casual}
%%%
% the following definition is from the file moderncvstyleclassic.sty
\renewcommand*{\cventry}[7][.25em]{%
\cvitem[#1]{#2}{%
{\bfseries#3}%
% \ifthenelse{\equal{#4}{}}{}{, {\slshape#4}}% I changed this line (with comma) ...
\ifthenelse{\equal{#4}{}}{}{ {\slshape#4}}% ... into this one (without comma).
\ifthenelse{\equal{#5}{}}{}{, #5}%
\ifthenelse{\equal{#6}{}}{}{, #6}%
.\strut%
\ifx&%
\else{\newline{}\begin{minipage}[t]{\linewidth}\small#7\end{minipage}}\fi}}
%%%
\firstname{John}
\familyname{Doe}
\begin{document}
\section{Education}
\cventry{December 2012}{Master of Science in Chocolatology}{University of Candyland}{Sugartown}{A+ with Golden Gummy Bear}{I am the chocolate-man.}
\end{document}

instead of redefining the whole command yourself also consider using xpatch:
\usepackage{xpatch}
\xpatchcmd\cventry{,}{}{}{}
this line replaces the first occurence in the macro text of , by the empty string - i.e. removes it.
Here is also a nice documentation of how the command works.
Obvious comment, but in case you want to be able to switch between having and not having the comma, you can define a new command \cventrynocomma like this:
\newcommand*{\cventrynocomma}[7][.25em]{%
\cvitem[#1]{#2}{%
{\bfseries#3}%
\ifthenelse{\equal{#4}{}}{}{ {\slshape#4}}%
\ifthenelse{\equal{#5}{}}{}{ #5}%
\ifthenelse{\equal{#6}{}}{}{ #6}%
\strut%
\ifx&%
\else{\newline{}\begin{minipage}[t]{\linewidth}\small#7\end{minipage}}\fi}}
From the file moderncvstyleclassic.sty, remove the comma and dot like following:
\renewcommand*{\cventry}[7][.25em]{%
\cvitem[#1]{#2}{%
{\bfseries#3}%
\ifthenelse{\equal{#4}{}}{}{ {\slshape#4}}%
\ifthenelse{\equal{#5}{}}{}{ #5}%
\ifthenelse{\equal{#6}{}}{}{ #6}%
\strut%
\ifx&%
\else{\newline{}\begin{minipage}[t]{\linewidth}\small#7\end{minipage}}\fi}}
It will remove the auto generated commas and dot from the \cventry.
It would be helpful if you composed a fully compilable MWE including
\documentclassand the appropriate packages that sets up the problem.While solving problems is fun, setting them up is not. Then those trying to help can simply cut and paste your MWE and get started on solving problem.
– Peter Grill Dec 12 '12 at 04:12