Date: 2007nov3 Updated: 2017oct28 OS: Linux Q. Linux: Is there any Linux stuff you recommend not using? A. Yes, here a partial list. Obsolete Replacement Comment -------- ----------- ------- compress gzip gzip compresses more gzip bzip2 bzip2 does a better job for large files bzip2 xz xz is better than bzip2 for large files sendmail postfix sendmail's config file is nuts telnet ssh telnet isn't safe perl php perl is great but php is better for websites K&R C ANSI C ANSI has function prototypes cc gcc The GNU C computer is nicer courier popd dovecot Fedora switched proftpd vsftpd Fedora switched init / upstart systemd Fedora switched ssh1 ssh2 ssh1 has been compromised - disable in /etc/ssh/ssh_conf MD5 SHA1 The MD5 hash has some collisions SHA1 SHA2 SHA1 has some collisions DES AES DES is getting hackable WEP WPA2 (for wireless security) WEP was hacked make jam Make is too labour-intensive localtime() localtime_r() localtime() isn't thread safe