October 6, 2015: LEDA 6.4 Free Edition now released for MacOS! Download here.     

about us

Quappa Inc.

your only US source for LEDA
your local partner for web design
expert on research and market studies

Digsy discovers what your data already know

Extract patterns, reveal dependencies, and predict the future?

... Digsy can help.


web design

web development


customized expert studies

market analyses reports

market entry studies

LEDA free edition

the LEDA Free Edition can be used by all kinds of users and for all standard purposes such as product and software development.


#1 library of efficient data types and algorithms

... for industry and academia!

LEDA Numbers

exact computations and integers with arbitrary length

... fully compatible with CGAL 4.5

LEDA docs

download the LEDA book

... guides, manuals, tutorials, and papers

graphic design

images inspire and express

we create icons, logos, and buttons


web content is a fusion

we write its language, art, and technology


we create your forms and online events, and set up your web storage data bases


we promote your site, set up social media presentations and optimize your content for search engines