FREECO @ Onward! ‘11

Workshop summary

The history of programming languages shows a continuous search for new composition mechanisms, which are better suited for structuring increasingly complex software systems into modules that can be developed and reused independently. Well-known examples are procedure calls, object aggregation, function composition, inheritance, delegation, mix-ins, aspects, andsoforth. Composition mechanisms can address various forms of composition of objects or components at the level of their behavior or interactions, e.g., by design patterns, contracts or explicit protocols. They can be general-purpose, but there is also a wide variety of domain-specific compositions, which are applicable for certain categories of applications. 

However, most languages adopt a very small and fixed set of composition mechanisms, usually with explicit notation and predefined semantics. If a language does not provide any mechanisms with the required compositional behavior, programmers need to write workarounds in the application program, which typically have a negative impact on the quality of the software. Alternatively they may introduce the new composition mechanisms through macros, libraries, frameworks or language extensions, which also negatively affects the application if it is not well-integrated  with the application program.

This workshop intends to stimulate research in program-ming languages and software development by exploring the notion that languages should not offer a limited set of fixed composition mechanisms, but allow for flexibility, a wide variety of compositions, domain-specific and tailored compositions, or programmable compositions of various program artifacts.

2nd Workshop on Free Composition

Onward! 2011, Portland, Oregon

an artist impression of a Star Wars ‘FREECO bike’ (

October 23, 2011
Portland, Oregon

@Onward! 2011

Workshop on Free Composition

Latest news & changes

post-workshop info, incl. slides

papers available for download

announced invited talks by Crista Lopes & Klaus Ostermann!

updated submission information

website live

nov 3:

oct. 10:

sept. 13:

july 27:

may 26:

Contact information

FREECO 2011 is organized by:

    Christoph Bockisch (University of Twente)

    Lodewijk Bergmans (University of Twente)
    Dean Wampler (Think Big Analytics, Inc.)

mail the organizers at:


(replace underscores with dots)

freeco 2011 Onward! workshop: towards Free Composition of software modules

FREECO@ONWARD2011 is a  FREECO initiativeshapeimage_2_link_0

thanks to all the participants for a fruitful workshop!

Workshop took place on October 23:

check out:

  1. the papers

  2. the presentation slides

  3. the workshop poster