Jonathan Frech’s homepage


logging since 2015, hosts digital projects of mine including but not limited to quines, poetry, simulations, proofs, imagery and thoughts of general nature.

Esoteric Languages

soteric languages explore the space of all pos­si­ble instruction directives without the bur­den­some constraints of usability. Major publicized esolangs of mine include:


krrp. A functional turing complete esolang focussing on cryptic conciseness whilst preserving capability. It currently has one interpreter, written in pure C. See krrp on GitHub and my krrp an­nounce­ment post.

A krrp example: prime number generation.

01 ![prime?]^n:
02  ,^d: ?<dn
03   ?%nd @+d1
04   0 1. 2.
05 \L [filter]
06  ;[prime?]
07  [range]2$99.

The above krrp program calculates all primes below a hundred. Try it online!


Zpr’(h. A symbolic, directionally super-lazy esoteric programming language I wrote in the tenth week of the year 2020. See Zpr’(h on GitHub and my Zpr’(h an­nounce­ment post.

A Zpr’(h example: prime number generation.

01 <| prelude.zpr
02 (prime? .p) |> (not (any \
03     (section @ | p) (range 2 p)))
04 primes |> (filter prime? \
05     (drop 2 |N0))
06 main |> (take 10 primes)

Joy Assembler

Joy Assembler. Frustrated with the lack of an ab­stract yet primitive and hardware-emulating toy assembler, I wrote one myself. You can find its currently only interpreter on GitHub.

Free Software

ree software is much more than only visible: free software at its core values a user’s fundamental rights. It is adherence to this value structure which makes software free.
Yet, most free software can also be viewed. I currently host most of my major public projects on GitHub; whilst I am a fond user of the version con­trol system git, on the political side I have to admit being torn using the eight-legged feline ser­vice overseen by Redmond – its assumed reliability being the major deciding factor.


EIS is Neil Sloane’s collection of over 300’000 integer sequences, five of which were contributed by myself; ref. my OEIS Userpage.

My contributions

My contributions to the OEIS:

  2016-11-18 authored A278328 @; blog post
  2017-04-19 authored A285494 @; blog post
  2017-05-04 authored A286193
  2017-06-04 authored A288040
  2017-06-05 implemented A052018
  2019-09-07 authored A325902 @; b325902.txt, blog post
  2019-09-12 computed b-file A055474 @; b055474.txt
  2019-09-12 computed b-file A055480 @; b055480.txt
* 2019-10-28 computed term A056154(13) @; post, paper
  2019-12-01 computed b-file A328012 @; b328012.txt
  2019-12-01 computed b-file A172987 @; b172987.txt
  2020-10-21 computed b-file A086136 @; b086136.txt
  2020-10-21 computed b-file A045096 @; b045096.txt
  2020-10-21 computed b-file A037772 @; b037772.txt
  2021-04-04 computed b-file A087891 @; b087891.txt
  2021-04-07 computed b-file A265546 @; b265546.txt
  2021-04-07 computed b-file A161602 @; b161602.txt
  2021-04-07 computed b-file A039334 @; b039334.txt
  2021-04-17 computed b-file A084433 @; b084433.txt


rivacy. By requesting my web pages, request’s time code, its URI, your IP address and user agent is being logged for up to a week my self-written go server to ensure operational stability. My VPS provider claims to log neither DNS requests nor server requests to any of my sites. If you want to view or delete your log files, please contact me
Naturally, should you choose to use one of my multi-user interactive web pages, actions within them are stored in working memory and parts distributed to all connected clients.
Currently, none of my provided APIs gather data extending the above, though for some services in the future the necessity of gathering might arise.
Other than the above, no data is collected. With overall low ECMAScript usage, banishing any and all third party scripts, I do neither deploy malicious trackers, cookies of any kind nor do I aggregate any data in any form. No data is given to third parties and SSL is strongly encouraged; all certificates are generously provided by Let’s Encrypt.

Licensing Thoughts

icensing thoughts. Unfortunately, I have not yet decided if I want my non-source-file work to be free. As such, I have for now left those unlicensed:

Web Content

Usage of my web content. All forms of media excluding non-artful source code (the following quine is an example of an artful source file) are not currently licensed. If you wish to use them, please contact me.
Any other source files are licensed under the Expat / MIT License.
Further licensing information specific to my blog can be found at


Deployed fonts. All third-party fonts used on my web pages are licensed under the Open Font License. These fonts include IBM Plex (both Sans Condensed and Mono) and STIX (both Math and Text).
Some fonts are hand-crafted and may be published in the future.


mprint. The domains,,,, and are together with all their subdomains operated by solely myself, Jonathan Frech. For E-Mail inquiries, please click here. If instead you would like to write me a letter, please click here.

Jonathan Frech’s homepage; last edited 2021-06-15.