Complex sentence: Currently SETI@Home is a test bed for further development not only of BOINC but of other hardware and software (database) technology that under SETI processing loads can be more bleeding edge than leading edge.
Split into simpler sentences: Currently SETI@Home is a test bed for further development not only of BOINC but of other hardware and software (database) technology. Under SETI processing loads these experimental technologies can be more bleeding edge than leading edge.