http://books.google.co.in/books?id=oeypBCDn9aEC&pg=PT165&lpg=PT165&dq=gcj+compiler+means&source=bl&ots=TfWtoh-Rfq&sig=M_NRgG_mCg9_Mkx6aG9bMYkc0I8&hl=en&ei=SOnmTvSJEc7LrQentvS5Bw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCYQ6AEwAA#v=onepage&q=gcj%20compiler%20means&f=false
see the above link