HelenOS sources

umdf_topmost      335 uspace/app/sysinst/sysinst.c 	params.flags |= umdf_topmost | umdf_center;
umdf_topmost     1217 uspace/app/sysinst/sysinst.c 	params.flags |= umdf_topmost | umdf_center;
umdf_topmost     1242 uspace/app/sysinst/sysinst.c 	params.flags |= umdf_topmost | umdf_center;
umdf_topmost      113 uspace/lib/ui/src/msgdialog.c 	if ((params->flags & umdf_topmost) != 0)
HelenOS homepage, sources at GitHub