\input regression-test.tex
\documentclass{article}
\usepackage[ngerman,english]{babel}
\usepackage[
  languages={en,de},
  targetlang=babel
]{langselect}
\begin{document}
\START
\TYPE{target=\olsTargetLanguage}
\TYPE{branch=\lende{EN}{DE}}
\lende{English text}{deutscher Text}
\END
\end{document}