Clarify project objectives and limits in scope

[wdconinc]

The project README.md should identify what this project aims to do, and what it does not aim to do. This includes:

• which cernlib libraries are within scope,
• whether paw, pawX11, paw++ are within scope,
• what level of testing is anticipated,
• what time horizon is anticipated for support.

[wdconinc]

nanocernlib

A collection of commonly used cernlib routines packaged with cmake to easily build on modern systems.

Scope

This project aims to provide a scaled down cernlib distribution to support legacy code on modern systems.

• The scope includes Monte Carlo event generators for which no suitable alternatives are available.
• The scope excludes interactive analysis environments (paw) and the particle simulation libraries (geant3).

The cernlib routines were written for 32-bit architectures. In several instances, coding practices were used that may not produce correct results on 64-bit architectures. Although we are not aware of any specific deficiencies in these routines, users are strongly encouraged to test their application code extensively for the correct performance before relying on this work.

Performance

This project aims to allow legacy code to compile with default compiler flags. Specifically, there are no attempts to pacify compiler flags such as -Wall and -Werror. Often, substantial code changes are required to address the reasons for these warnings, and these changes may introduces further problems.

Support

This project was started out of the real need to narrow the support surface to the minimum necessary, and to unify a number of disparate attempts at keeping cernlib operations in the face of technological advances. We anticipate supporting releases for a period of 2 years on the default compilers for the following operating systems: Ubuntu (LTS), Red Hat/CentOS (latest release).

Contributing

Bugfixes are welcome. Please fork and submit a pull request.