Ok - I just thought - that lack of W3 could be possible reason of whole mess... I did sepia-repl ... Actually - here is exact sequence: 1. I started emacs 2. I opened Sepia.pm 3. M-x load-library RET sepia RET 4. M-x sepia-repl RET . After it - emacs window splited onto 2 pans , in second pan that has "*sepia-repl*" title - - I see "Sepia REPL finished" 5. I run - M-x sepia-rebuild RET - and here emacs stuck... There are no any error messages ... Just cursor get form of "clock" and emacs stop to respond... That is it... I tried AIX and MS windows... Same result...