Note: This information has not been updated since original creation, and may no longer be up to date. It is still here for reference. Up to date information on the toolkit can be found here: The DITA Open Toolkit

Requirement/Problem:
Topic merge in previous releases are written in xsl which calls document() to load different xml files into memory. But xsl transformation engine won't release the document tree once it gets loaded. This caused out of memory exception when merging large documents. Another bug in current topic merge is that the intermediate merged file lost the structure information in dita map and caused the structured toc can't be reflected in output.
Design Description:
Removed information. The description did not accurately describe the latest topicmerge program and was causing confusion.