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NEWS:
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The CCP4 Program SuiteThe CCP4 program suite is a collection of disparate programs covering most of the computations required for macromolecular crystallography. They have been collected and developed under the auspices of the Collaborative Computing Project Number 4, in Protein Crystallography, supported by the UK Science and Engineering Research Council (serc) since 1979 and currently the Biotechnology and Biological Sciences Research Council (bbsrc), and coordinated at Daresbury Laboratory. The Project aimed to support collaboration between those working on such software in the UK, and to assemble a comprehensive collection of it to satisfy the computational requirements of the relevant UK groups. The results of this effort are also made available for distribution to academic and commercial users outside the UK. The distribution, described herein, is often loosely referred to as `CCP4', but is properly `The CCP4 Suite'.
Collaboration on the development of the suite was previously extended to the whole of Europe under the auspices of the European Science Foundation Network for the European Association for the Crystallography of Biological Macromolecules (esf/eacbm).
CCP4 is overseen by two committees: Working Group 1, largely comprising heads of groups, normally meets annually and makes general policy. Working Group 2 meets more frequently and coordinates the developers. The current chairmen of WG1 and WG2 are Neil Isaacs (Glasgow University) and Phil Evans (MRC LMB) respectively. Working Group 2 has a representative of industrial users, currently Tadeusz Skarzynski of Glaxo. The various CCPs are coordinated by a bbsrc steering committee. Currently (April 1998), bbsrc funds positions at Daresbury -- Sue Bailey, Secretary and Martyn Winn , and 1 position at York University -- Garib Murshudov . Alun Ashton and Peter Briggs also currently work for the project at Daresbury, funded by receipts from industry. Liz Potterton is contracted to work on a Graphical User Interface for the Suite.
Unlike many other packages, particularly for small molecule crystallography, the CCP4 suite is a set of separate programs which communicate via standard data files, rather than all operations being integrated into one huge program. This has some disadvantages in that it is less easy for programs to make decisions about what operation to do next--though it is seldom a problem in practice--and that the programs are less consistent with each other (although much work has recently been done to improve this). The advantage of loose organisation is that it is very easy to add new programs or to modify existing ones without upsetting other parts of the suite. This is the approach successfully taken by Unix. Converting a program to use the standard CCP4 file formats is generally straightforward, and the philosophy of the collection has been to be inclusive, so that several programs may be available to do the same task. The components of the whole system are then a collection of programs using a standard subroutine library to access standard format files (and a set of examples files and documentation) available for both the VMS and Unix operating systems. Most of the programs are expected to be written in standard Fortran--currently the obsolete FORTRAN77 version.
To use the programs the user must assign input and output files, including library and scratch files where necessary (though defaults are usually defined), and run the programs. Often an output file becomes the input to the next step, and system parameter substitution may be used to create filenames in a systematic way. Most crystallographic calculations involve a series of steps in which no decisions need be made until the end, and a command file provides an easy way of chaining calculations.
Standard file formats are defined for the principal sorts of data used in crystallography: reflection data; density maps; and atom coordinates. In defining these formats, a number of trade-offs have to be made between efficiency (in space and access time), flexibility, portability, and simplicity of use. Since the data formats form the core of the suite, they are described in more detail in elswhere in the CCP4 manual. The formats used in the CCP4 suite share many characteristics with those used in other packages.
The programs are distributed in source form, so they can be studied (don't look too closely!), modified and fixed by recipients, in contrast to most commercial software. This means that you need Fortran and C compilers to build the suite, although there are freely-obtainable Fortran and C implementations. There are freely-available Unix implementations for PC-type boxes at least, and the combination of a sufficiently well-resourced top-end PC and, say, the Linux operating system and compilers reputedly makes a competent environment for scientific computing.
In addition to the CCP4 suite proper, some software is `aggregated' to the suite and distributed with it. An example is the rasmol system.
There is a policy of continual technical and scientific updates to the suite. Where existing programs have been incorporated into the suite they have often subsequently undergone considerable modification above that needed to use the CCP4 file formats.
Please see the distribution conditions for the suite. In particular, please note that any publication arising from use of the CCP4 program suite should include a reference to the the program, see references and [Collaborative Computational Project, Number 4, 1994] given as:
COLLABORATIVE COMPUTATIONAL PROJECT, NUMBER 4. 1994. ``The CCP4 Suite: Programs for Protein Crystallography''. Acta Cryst. D50, 760-763.
Such citations may be valuable to us in the future in maintaining funding. In addition, authors of specific programs should be referenced where applicable--see the program's documentation and/or output.
The suite is available without cost to academic institutions, subject to a completed license form being returned to the CCP4 secretary; but a charge is made to commercial users who should contact the CCP4 secretary to make arrangements. Please note that all charges for the suite are used for CCP4 activities. See the CCP4 License and Conditions section for more details.
FTP SiteThe software is available by anonymous ftp from: ftp://ccp4a.dl.ac.uk/pub/ccp4. A licence agreement is included with the distribution permitting the use of the suite on any machine at the named site (but see above about commercial usage before downloading).
FTP Mirror sites
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