User interfaces for modern applications must support a rich set of interactive features. It is commonplace to find applications with dependencies between values manipulated by user interface elements, conditionally enabled controls, and script record-ability and playback against different documents. A significant fraction of the application programming effort is devoted to implementing such functionality, and the resulting code is typically not reusable.

A user interface, such as a dialog, assists a user in synthesising a set of values, typically parameters for a command object. Code for "command parameter synthesis" is usually application-specific and non-reusable, consisting of validation logic in event handlers and code that controls how values of user interface elements change in response to a user's actions, etc. These software artifacts are incidental - they are not explicitly designed and their implementation emerges from a composition of locally defined behaviors.

Large scale software is composed of libraries produced by different entities. Non-intrusive and efficient mechanisms for adapting data structures from one library to conform to APIs of another are essential for the success of large software projects. Concepts and concept maps, planned features for the next version of C++, have been designed to support adaptation, promising generic, non-intrusive, efficient, and identity preserving adapters. This paper analyses the use of concept maps for library composition and adaptation, comparing and contrasting concept maps to other common adaptation mechanisms. We report on two cases of data structure adaptation between different libraries, indicating best practices and idioms along the way. First, we adapt GUI controls from several frameworks for use with a generic layout engine, extending the application of concepts to run-time polymorphism. Second, we develop a transparent adaptation layer between an image processing library and a graph algorithm library, enabling the efficient application of graph algorithms to the image processing domain.

This paper describes the design and implementation of an algorithmic differentiation framework in the Axiom computer algebra system. Our implementation works by transformations on Spad programs at the level of the typed abstract syntax tree -- Spad is the language for extending Axiom with libraries. The framework illustrates an algebraic theory of algorithmic differentiation, here only for Spad programs, but we suggest that the theory is general. In particular, if it is possible to define a compositional semantics for programs, we define the exact requirements for when a program can be algorithmically differentiated. This leads to a general algorithmic differentiation system, and is not confined to functions which compute with basic data types, such as floating point numbers.

UNLABELLED: X-ray crystallography is the most widely used method to determine the 3D structure of protein molecules. One of the most difficult steps in protein crystallography is model-building, which consists of constructing a backbone and then amino acid side chains into an electron density map. Interpretation of electron density maps represents a major bottleneck in protein structure determination pipelines, and thus, automated techniques to interpret maps can greatly improve the throughput. We have developed WebTex, a simple and yet powerful web interface to TEXTAL, a program that automates this process of fitting atoms into electron density maps. TEXTAL can also be downloaded for local installation. AVAILABILITY: Web interface, downloadable binaries and documentation at http://textal.tamu.edu