This file gives syntax highlighting of LotusScript in jEdit (tested with 4.1 and 4.2pre1). Put it into (jEdit home)/modes and add these lines to the (jEdit home)/modes/catalog file:

<MODE NAME="lotusscript" FILE="lotusscript.xml" FILE_NAME_GLOB="*.{ls,lss}" />

Original post at jedit.org
Added Me. Whitespace control added, thanks Alexander Knie!