Welcome to Greg Koenig's homepage on SDF.

This is a photograph of me with the Cray-1 supercomputer at the Computer History Museum taken in May 2016. The museum has information online about Seymour Cray and the Cray-1. I have been very blessed during my career to have had opportunities to work with supercomputers at places like Argonne National Laboratory, the National Center for Supercomputing Applications, and Oak Ridge National Laboratory so getting a chance to see the Cray-1 exhibit in person was very special to me.

SDF, the Super Dimension Fortress, is a non-profit public Unix shell provider that has existed in various forms since 1987. In practice, SDF is a social club where programmers, scientists, hackers, students, teachers, musicians, artists, and many other interesting people gather to exchange ideas. SDF has been described as an "elegant" social experience on the Internet, an alternative to more mainstream sites such as Facebook. Indeed, overlooking the social aspect of SDF is to miss the point entirely.

Some of the fun things to do on SDF:

• Shell access. You'll want to at least get yourself validated. Being validated allows you to have a standard Unix shell account accessible by pointing your SSH client at tty.freeshell.org. This is a round-robin alias that selects from several hosts in the SDF NetBSD cluster. Users who join ARPA level can SSH to arpa.freeshell.org which is a special ARPA-level node in the cluster. Fun things to do at the shell prompt include programming as well as classic games like nethack.
• aNONradio, SDF's underground Internet radio. A number of very talented people share their creativity here by working as volunteer DJs on a variety of shows. Electronic music is extremely popular (see, especially, the Intergalactic Wasabi Mix which is mixed live four days per week by DJ snowdusk) but there are several other types of music as well as several spoken-word shows.
• irc.sdf.org, SDF's IRC server. People hang out on #sdf for general socializing.
• SDFARC, the SDF Amateur Radio Club.

I have been a member of SDF since 2005. During that time, I've met many great people and have learned from a variety of perspectives through countless hours of conversation. Feel free to catch me on IRC or send me an e-mail and introduce yourself!