That's a generic term in OO. It refers to objects whose instances are uncomplicated and small. That is typically done by keeping the real data in some kind of container which does the management. A blessed scalar key to the class global container is then a lightweight object.

It's sometimes a bit of a cheat - the container and its management methods are likely just as complicated as a direct implementation would be.

There's a lot of information here, just browse the list in this link to flyweights.

many thanks to zaxo :-)

LDO abbreviated from Lightweight Distributed Object and it is the specification for serializing objects using XML or a binary format, for encoding remote requests as objects to be transmitted. It is an API for using the remote requests and serialization. LDO implementations are available for Python and Perl. This was previously called Lotos and listed in the XML Resource Guide on XML.com using it's old name. For further specifications on LDO, visit http://www.ntlug.org/cgi-bin/cvsweb/LDO/