"DB-Engines is an initiative to collect and present information on database management systems (DBMS). In addition to established relational DBMS, systems and concepts of the growing NoSQL area are emphasized.

The DB-Engines Ranking is a list of DBMS ranked by their current popularity. The list is updated monthly.

The most important properties of numerous systems are shown in the overview of database management systems. You can examine the properties for each system, and you can compare them side by side.

In the database encyclopedia terms and concepts on this topic are explained.

DB-Engines has been created and is maintained by solid IT." - from DBEngines.


The DB-Engines Ranking ranks database management systems according to their popularity. The ranking is updated monthly.


Each database gets a detailed single-page report


Pipi needs to be available in many different languages.

I use an automated build process to create a separate User Interface (UI) in each language, using separate code and databases.

One problem is the translation of the strings used in the UI.

Another problem to solve is what fonts to use.

As it turns out, Google has a project called Noto ("No Tofo") to provide a font that could be used for the many writing systems described by Unicode and 6,500 + languages.

"Noto is a collection of high-quality fonts with multiple weights and widths in sans, serif, mono, and other styles, in more than 1,000 languages and over 150 writing systems." - Noto Dashboard.

Noto is open-source and freely available from GitHub. One repository per font, e.g., Tibetan, Mongolian, and Latin.

SIL International is involved. I'm embedding their excellent keyman project on the Ajabbi websites to give people a web keyboard in their own language. Several thousand different language keyboards are now available.

This website is presented in Noto Sans font, which I'm making the default font for all Ajabbi websites and the UI.

For example, a Balinese version of Ajabbi would use the NotoSansBalinese font. However, a logged-in administrator or user can change that font to another Balinese font.

There are regular releases. Here are 11 releases from May 2024.

Further information


Noto Fonts: Preserving Endangered Languages | S. Zaraysky/M. Jeziorek/D. Crossland | ATypI 2020

Creating Noto for Google

TUG 2020 — Steven Matteson — The road to NOTO

Self-hosting fonts explained (including Google fonts) // @font-face tutorial


Ajabbi.com now has a draft website, along with several subdomains.

The problem to solve was that the domain and each subdomain needed to go into their own separate root directory to simplify FTP uploads. There are 20,000 pages of documentation in pre-rendered HTML to upload, which is not a trivial issue.

The different websites on Apache Web Server all use the same cPanel to manage them. I have never used Apache before. Pipi 3 and 4 used IIS. So a bit of a learning curve for me.

According to Wikipedia

"cPanel is web hosting control panel software developed by cPanel, L.L.C. It provides a graphical interface (GUI) and automation tools designed to simplify the process of hosting a web site to the website owner or the "end user". It enables administration through a standard web browser using a three-tier structure. While cPanel is limited to managing a single hosting account, cPanel & WHM allows the administration of the entire server. ..."

The version I use is called Plesk.

The .htaccess file had to have a redirect added and written in Perl, which I have yet to learn, so GreenGeeks provided excellent support and edited the file.

It was

RewriteRule ^(.*)$ /subdirectory/$1

It is now

RewriteRule ^(.*)$ /ajabbi.com/$1

And it works perfectly.

Useful references to .htaccess

DNS tools

Recently, I created several static websites on a hosting account at GreenGeeks, a Canadian company.

I also had to set up some email servers at nzdomainregistration.

This involved correct DNS settings, which then had to be tested.

Some of the valuable tools were.

  • DigWebInterface
  • MXToolbox
  • IntoDNS
  • Cloudflare

The support from GreenGeeks was excellent. Barry at NZ Domain Registration was exceptional as well. I also found a lot of helpful information on the forums at CloudFlare.


A useful website structure

The time has come to create public-facing websites for Ajabbi so that people can use the Pipi software. There is a 20,000-page backlog of autogenerated and human-written documentation to put somewhere. Here is an experimental structure to test on people to find out what works best. This structure is likely to change a lot based on feedback.

  • ajabbi.com
  • blog.ajabbi.com
  • developer.ajabbi.com
  • docs.ajabbi.com
  • foundation.ajabbi.com
  • research.ajabbi.com
  • workspace.ajabbi.com


A website where people can find general information, sign up and log in.

  • About (contact, history)
  • Plans (pricing, features)
  • Support (docs, training, whitepapers, events)


A website for Mike Peters to write about how Pipi was developed.


A website where developers can get detailed information about building apps to run on the platform.

  • IDE
  • Samples (GitHub)
  • Technical support

  • Translations


A website where developers can get technical information about the platform.

  • How to guides
  • Versions
  • Roadmap


A website for the non-profit organisation that will get any net income and then redistribute it.

  • Grants


A website about experimental research into complex adaptive systems and machine learning computing.

  • Machine learning algorithms
  • Research publications
  • Core documentation
  • Complex adaptive systems


A website about the domain applications, including live demos.

  • Film
  • Health
  • Transport

  • Ecological restoration
  • Production forestry

The next steps in building these websites include;

  • Find some low-cost hosting for thousands of static web pages about documentation. (done)

  • Configure email server. (done)

  • Register subdomains. (done)
  • Draft up skeleton websites. (done)
  • Use robots.txt to stop web crawlers, especially Google, from indexing and caching pages likely to disappear. (underway)
  • Upload sample documentation to check site-wide navigation and usability. (underway)
  • Organise some meetings to get public feedback and suggestions for improvement.
  • Repeat the design and test process.

  • Build, test, and deploy a DNS engine to automatically create DNS records via the command line or API at a Domain Registrar.
  • Build, test, and deploy an FTP engine that automatically uploads webpages to a host as they are created by Pipi using the CMS Engine.
  • Render and bulk upload working documentation.
  • Edit robots.txt to allow web crawlers, especially Google, to index and cache pages.

  • Add XML site map.