UNIX, Linux, C, C++, Java, *SQL, PHP[3,4,5], Perl, Python, Shell Scripting, embedded/realtime applications, communication protocols, X/Motif/Java/Qt GUI development, Pascal, BASIC, FORTRAN. Arduino, Pi and other SBC. Operating Systems Server Software Sendmail, postfix, qpsmtpd, Scalix, PostgreSQL, MySQL, NFS, Samba, Apache, Tomcat (jsp), SSH, SSL, FTPD, squid, gnome/KDE, POP3, IMAP, LPD, CUPS, custom TCP proxy software, FWTK, SNMP, DNS (bind), X Windows/XFree86, Ingres DB, Netware, Linux Netware Server (mars) and much much more.