I've been reading notsofast's article about security. He said the safest way to run an altcoin wallet is to compile an open source code. Any guides how to do it? Is it called to run a client from a command line?
Not exactly. Compiling means turning the source code (the written commands) into machine readable code that a computer can run efficiently. It does involve typing a number of commands at your shell prompt, but you only compile a program once, after which you can run it any way you want. Compiling your own software is considered safer than running binaries compiled by others because the latter are more difficult to examine for back doors and other malicious features.