Eclipse is an open-source community project that is focused on building an extensible development platform: a suite of software tools that assist in the writing of software. Primarily it is used as a Java integrated development environment (IDE) but has been adapted for many other languages including python, C, C++, and FORTRAN.
an interface for array-oriented data access and a library that provides an implementation of the interface. The netCDF library also defines a machine-independent format for representing scientific data.
Guy Steele's keynote at the 1998 ACM OOPSLA conference on "Growing a Language" (mostly about JAVA) discusses the importance of and issues associated with designing a programming language that can be grown by its users.