Davide Ancona		Mirko Viroli

Guest Editorial

Dear readers,

the OOPS special track at the 2004 ACM Symposium on Applied Computing (SAC 2004) on Object-Oriented Programming Languages and Systems was the first edition of a hopefully long series promoting the development of extensions and enhancements to the prevalent object-oriented languages and standard systems.

The track solicited contributions on design, theoretical, and architectural aspects covering a large spectrum of topics, including, programming abstractions, advanced type mechanisms and type safety, multi-paradigm features, language features in support of open systems, aspect-oriented and component-based programming, reflection, and program structuring and modularity.

A high number of high quality submissions was attracted, among which 10 were selected for publication in the proceedings, and present at SAC 2004. Then, the authors of 6 papers were invited to submit to this JOT special issue a full article containing an extended version of the conference version.

The papers contributions cover hot topics in theory, design and implementation of mainstream object-oriented languages and component-based systems.

We are grateful to the authors for submitting these contributions, to the OOPS 2004 program committee and the external referees of the journal papers for reviewing the submissions. The second edition of OOPS will be held, again as a special track of SAC 2005, in Santa Fe, NM, USA, March 13–17, 2005.