Thousands of reusable components help you develop your applications by standing on the shoulders of previous developers.

By developing with the Eiffel libraries you gain the benefit of increased maintainability because your code is reusable and readable. You also get improved debugging and greater doe reliability through Design by Contract™.

Below is the list of the most important and used Eiffel libraries:


Covered by the open-source IFFEL License, EiffeBase is one of the principal contributions of Eiffel: a library of fundamental structures and algorithms covering the basics of computing, and resulting from a “Linnaean” effort at a general-purpose taxonomy of computing structures. The library includes core classes used in all Eiffel systems, providing classes needed for exception handling, standard arithmetic operations, data structures basic arithmetic conversions.

EiffelVision 2

The extensive multi-platform graphical library for producing modern GUI applications that will run on Windows as well as Unix, Linux, VMS and other X-based platforms.

WEL (Windows Eiffel Library)

WEL is an Object-Oriented encapsulation of the Win32 API. It provides all the necessary classes for creating windows, dialogs, controls, and everything you need a build a complete Windows based application.


Provides support classes both building and reusing existing software components written using the Microsoft Component Object Model standard. In addition to the EiffelCOM Wizard that is part of EiffelStudio COM development and reuse is made much easier than traditional methods.


The client-server library for exchanging object structures across the network, between identical or different machine architectures.


A versatile library for incorporating date and time functionality into your programs.


EiffelStore provides facilities for interfacing an application with various Database Management Systems (DBMS), allowing for data-driven applications. Support is included for Oracle, SQL, Ingres, Sysbase and any ODBC compliant database.


Includes the main components needed to build multithreaded systems. It is supported by the Eiffel Software compiler and run-time on Windows, Linux, FreeBSD, LinuxPPC, Solaris, SGI, VxWorks, LynxOS, CRAY and Unixware.


The Java interface library that allows you to call Java routines or attributes from your Eiffel code. It uses the Java Native Interface (JNI) provided by the Java Development Kit (JDK)..


Web interface library that makes it possible to write Eiffel systems that interact directly with the web. You can build and interact with HTML web forms to provide dynamic page content to your users. EiffelWeb allows for building CGI as well as Fast CGI scripts.


Complete textual analysis facilities and make it possible to build and apply lexical analyzers to many different languages.


Provides complete document parsing capabilities. It can be used to build compilers, interpreters and other software development tools and to process documents of many different types. It provides a simple and flexible parsing scheme, resulting from the full application of object-oriented principles.