Hi, Your problem is not GATE related at all. It is based on common Linux knowledge ... So to understand your problem, you will have many more chances in ubuntu forums for example. I've just typed "lib socket ubuntu" in google (google is a nice tool), and found this as the first page: <a href="http://stackoverflow.com/questions/1438479/cannot-find-lsocket-compiling-problem-in-client-server-program">http://stackoverflow.com/questions/1438479/cannot-find-lsocket-compiling-problem-in-client-server-program</a> I think, and I hope this will help you solving your library dependencies problem. (try to locate your libsocket.so file and add the right path in your makefile) Ecat7 was not developed by the founders of GATE, and also it was developed in the 90's and never upgraded nor maintained. Hope you will succeed in using the ecat7 output ! Good luck, Simon <div class="gmail_quote">On Mon, Feb 25, 2013 at 1:02 PM, Saeed Heidary <<a href="mailto:saeedheidary79@gmail.com" target="_blank">saeedheidary79@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi gate users! it is for a long time that I could not install ecat! I don't know if there is any body has done it before or not! I dont know if the founders of GATE know , I bet they dont , users have been forgotten ! I have tried centOs, fedora, RedHat, Debian, and finally Ubunto 11.10 I added "happycoders-libsocket-dev" and "happycoders-libsocket" to solve the problem but nothing , the same error same error in ecat/utils cc -O -I.. -o matlist ./matlist.c ../libecat.a -lrpcsvc -lnsl -lsocket -lm ./matlist.c: In function ‘main’: ./matlist.c:22:3: warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default] /usr/bin/ld: cannot find -lsocket collect2: ld returned 1 exit status make: *** [matlist] Error 1 refering to Makefile.unix , you see LIBS = -lrpcsvc -lnsl -lsocket -lm # for solaris this error should be happen in solaris OS !! I dont know exactly , should I change the makefile or not!? Thanks to the all patient users _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.opengatecollaboration.org">Gate-users@lists.opengatecollaboration.org</a> <a href="http://lists.opengatecollaboration.org/mailman/listinfo/gate-users" target="_blank">http://lists.opengatecollaboration.org/mailman/listinfo/gate-users</a> </blockquote></div>