Hi pdfTeX fans, in the last few days I have fiddled around with application of AVL trees, and as an experiment replaced the linked list PdfDocuments in file pdftoepdf.cc by an AVL search tree. It was quite straight-forward. Once the coredumps go away, it works :-) The patch you find on my homepage: w w w . c i r c u i t w i z a r d . d e I use the nice AVL implementation GNU libavl by Ben Pfaff, it is compact, looks very mature/stable, extremely well documented, and it's unter the GNU Public License, Good. These AVL trees give a pretty high lookup speed, so one probably might give them a try for other dictionary lookup tasks within pdfTeX. (However I already failed miserably before, when trying to replace the fm_tab list for mapfile entries by such an AVL tree. The fm_tab list stuff is so widely scattered over many places within the pdftex sources, that a replacement by a search tree would be a major overhaul; but it seems to be possible. Anyway we have the nice hashing by Heiko.) The patch is still rather raw, but as it basically does the wanted, I thought I should push it out for discussion. Greetings Hartmut