[martin@aquaman apache-couchdb-0.8.1-incubating]$ couchdb
Apache CouchDB 0.8.1-incubating (LogLevel=info)
Apache CouchDB is starting.
{"init terminating in do_boot","libjs.so: cannot open shared object file: No such file or directory"}
Crash dump was written to: erl_crash.dump
init terminating in do_boot (libjs.so: cannot open shared object file: No such file or directory)
Searching for this error doesn't give much. The most useful hit I found was in Japanese, so just in case anybody else isn't able to use binaries from a yum repository and get the same error, try
ln -s /usr/local/spidermonkey/lib64/libjs.so /usr/lib/libjs.so
ldconfig