It's a pleasure to see how much faster they [students] are advancing [with DES] than with Prolog in the past

It's a pleasure to see how much faster they [students] are advancing [with DES] than with Prolog in the past.

A good and useful [Datalog] implementation is DES.

DES is an easy system to use and it is a nice way of learning more about Datalog while playing around with rules, statements and queries.

First of all I would like to thank you for the DES project. It is an amazing job and excellent resource for educational purposes.

I was very impressed with their download statistics. 35,000 downloads is very significant for an academic project. [Now, more than 70K]

They [features] are realized in an open source system and thus advance the state of art available for the academic and research communities.

Wow! [...] I'm especially excited about [sections] 5.9.2 and Debuggers aren't taking advantage of extra information I might  know: sometimes I just know that something's wrong, but often I know  "hey, this value's supposed to be (specifically) X!" That extra  information can absolutely guide what happened.

[DES] Is useful for learning deductive databases.

Bardzo dobrą edukacyjną implementacją Datalogu jest DES, dostępny pod adresem: Zawiera on także implementację języka SQL, jest więc doskonałym narzędziem do nauczania baz danych. [A very good educational implementation of Datalog is DES, available at: It also includes the implementation of the SQL language, so it is a great tool for teaching databases.]

[DES] includes some clever components such as the declarative debugger.

I very much sympathize with the authors for having built a freely available tool that students and teachers can find interesting and helpful in their undergraduate courses.

DES has implemented many powerful features and is an interesting and comprehensive system used in many domains and in education.

As a starting point, DES has a nice shell written in Prolog.

I'm looking at DES with great interest. ... DES seems to embody many interesting ideas.

Te escribo estas líneas para saludarte y felicitarte por tu trabajo en Datalog. [I write you to send greetings and congratulate you on your work in Datalog.]

Thank you so much for helping me in understanding Datalog. Really it has helped me a lot.

Thanks again for contributing such valuable experience to the IT community.

Why not just use or adapt an existing SQL parser? For example,

Primero de todo, agredecerte y felicitarte por el excelente trabajo que has realizado con DES. Ojalá hubiera tenido al alcance una herramienta como ésta cuando empecé a introducirme en las bases de datos deductivas años ha. [First of all, thank you and congratulate you on your excellent work on DES. I would liked to have such a tool when introducing myself to deductive databases years ago.]

The database connection is  very convenient. Thank you very much for implementing the DB access.

For sure, you are working on a fantastic system that has to be completed with the MySQL interface to become a masterpiece ! [This is available since version 2.0]

Thank you very much. DES system is really awesome !

I am working on datalog and I found DES which seems to work perfectly for what I am doing.

I've found your DES system useful as it allows me to easily modify the fixpoint computation so that I can examine the state of the extension table as it is being constructed.

This looks like a great system.

I enjoyed very much using the DES system since it is small and installs easily.

I implemented my own algorithm for dynamically/locally stratified Datalog. It was a hell of a job for me  :-)  Had I known your system, I could have saved some time.

I found your DES system in the application db of SWI-Prolog. I downloaded it and find it very useful for education.

Your software is working fine now, and I learned a lot of Datalog with it, for that many thanks (it's a good help for my course "Databases3)!

Thanks for developing the great DES tool. I tested ODBC connection to MSSQL 2008 on Windows 7, it worked like a charm. !

This is a comprehensive Datalog system, with support not just for full-fledged Datalog (with aggregation etc), but it also supports SQL and Relational Algebra queries. It has lots of example code, nice documentation etc. Good fun!!

After several years using our own relational algebra interpreter we chose to use your fantastic educational system DES.

I am now using DES in my course on logic programming [for teaching] and I like it very much!

More generally, Datalog should [be better known than it is]. Those who are curious about Datalog should check out the Datalog Educational System.

Thanks for making DES available!

All of this is quite easy!! And DES supports both, Datalog and SQL, in a really unique manner!

It is excellent pedagogical material.

Here is a link to the current DES Manual (a 377 pages “book”, new version 19.4.2016) ready for reading. This is a lot of material, not fully “synchronized” with our lecture, but useful nevertheless (and quite exceptional).