T. Kurt Bond schrieb am 23.03.2020 um 16:50:
> It turns out that the extra whitespace before and after the section
> headers in the body appears when I put \startcolumns[n=2] before the
> body text and \stopcolumns after it.  Here's the MWE, just slightly
> modified from your example:
>
> %%%% begin example
> [...]
> %%%% end example

The old columns environment was replaced a while ago with the newer
(although available since a few years) mixedcolumns environment.

A big difference between the old columns code and new code is that the
new code relies on a page grid which can lead to extra lines in the
output, because ConTeXt adds extra space to put text on the grid.

When you don't care about the grid you can disable it for the columns
environment but this has to be done also for headers which have their
own grid option.

Another option is to try the pagecolumns environment, which is another
environment for multi columns text but it's a very recent addition and
lacks some features like column balancing.

%%%% begin columns
\setuphead
   [chapter,section,subsection,subsubsection]
   [before={\blank[nowhite]},
    after={\blank[nowhite]},
    grid=no]

\setupwhitespace
   [medium]

\setuplist
   [chapter,section,subsection,subsubsection]
   [before={\blank[nowhite]},
    after={\blank[nowhite]}]

\setupcolumns
   [grid=no]

\starttext

\startcolumns

\completecontent

\chapter{Chapter}

\samplefile{knuth}

\section{Section}

\samplefile{weisman}

\subsection{Subsection}

\samplefile{weisman}

\subsubsection{Subsubsection}

\samplefile{weisman}

\stopcolumns

\stoptext
%%%% end columns

Wolfgang