\twocolitem{\_\_WXGTK12\_\_}{GTK 1.2 or higher}
\twocolitem{\_\_WXGTK20\_\_}{GTK 2.0 or higher}
\twocolitem{\_\_WXMOTIF\_\_}{Motif}
+\twocolitem{\_\_WXMOTIF20\_\_}{Motif 2.0 or higher}
\twocolitem{\_\_WXMAC\_\_}{Mac OS whether Classic (Mac OS 8/9 TARGET\_CARBON == 0) or Carbon (including Mac OS X TARGET\_CARBON == 1)}
\twocolitem{\_\_WXMGL\_\_}{SciTech Soft MGL (\_\_WXUNIVERSAL\_\_ will be also
defined)}