\begin{twocollist}\itemsep=0pt
\twocolitemruled{Platform}{Return tyes}
\twocolitem{Macintosh}{Return value is wxMACINTOSH.}
+\twocolitem{GTK}{Return value is wxGTK, {\it major} is 1, {\it minor} is 0. (for GTK 1.0.X) }
\twocolitem{Motif}{Return value is wxMOTIF\_X, {\it major} is X version, {\it minor} is X revision.}
\twocolitem{OS/2}{Return value is wxOS2\_PM.}
\twocolitem{Windows 3.1}{Return value is wxWINDOWS, {\it major} is 3, {\it minor} is 1.}