\twocolitem{\helpref{wxDC}{wxdc}}{The device context base class}
\twocolitem{\helpref{wxMemoryDC}{wxmemorydc}}{A device context for drawing into bitmaps}
\twocolitem{\helpref{wxMetafileDC}{wxmetafiledc}}{A device context for drawing into metafiles}
+\twocolitem{\helpref{wxMirrorDC}{wxmirrordc}}{A proxy device context allowing for simple mirroring.}
\twocolitem{\helpref{wxPostScriptDC}{wxpostscriptdc}}{A device context for drawing into PostScript files}
\twocolitem{\helpref{wxPrinterDC}{wxprinterdc}}{A device context for drawing to printers}
\end{twocollist}
\twocolwidtha{6cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{\helpref{wxThread}{wxthread}}{Thread class}
+\twocolitem{\helpref{wxThreadHelper}{wxthreadhelper}}{Manages background threads easily}
\twocolitem{\helpref{wxMutex}{wxmutex}}{Mutex class}
\twocolitem{\helpref{wxMutexLocker}{wxmutexlocker}}{Mutex locker utility class}
\twocolitem{\helpref{wxCriticalSection}{wxcriticalsection}}{Critical section class}