“11 An Ada program is composed of one or more program units. Program units may be subprograms (which define executable algorithms), packages (which define collections of entities), task units (which define concurrent computations), protected units (which define operations for the coordinated sharing of data between tasks), or generic units (which define parameterized forms of packages and subprograms). Each program unit normally consists of two parts: a specification, containing the information that must be visible to other units, and a body, containing the implementation details, which need not be visible to other units. Most program units can be compiled separately.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information

    “16 A package is the basic unit for defining a collection of logically related entities. For example, a package can be used to define a set of type declarations and associated operations. Portions of a package can be hidden from the user, thus allowing access only to the logical properties expressed by the package specification.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information

    “17 Subprogram and package units may be compiled separately and arranged in hierarchies of parent and child units giving fine control over visibility of the logical properties and their detailed implementation.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information

    “42.2/2 The specialized annexes define further predefined library packages and facilities with emphasis on areas such as real-time scheduling, interrupt handling, distributed systems, numerical computation, and high-integrity systems.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information

    “43 Finally, the language provides a powerful means of parameterization of program units, called generic program units. The generic parameters can be types and subprograms (as well as objects and packages) and so allow general algorithms and data structures to be defined that are applicable to all types of a given class.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information

    “1 Ada is a programming language designed to support the construction of long-lived, highly reliable software systems. The language includes facilities to define packages of related types, objects, and operations. The packages may be parameterized and the types may be extended to support the construction of libraries of reusable, adaptable software components. The operations may be implemented as subprograms using conventional sequential control structures, or as entries that include synchronization of concurrent threads of control as part of their invocation. The language treats modularity in the physical sense as well, with a facility to support separate compilation.” —:Ada-Europe’s Ada Reference Manual: Section 1: General See legal information

    “2 Finally, a predefined environment of standard packages is provided, including facilities for, among others, input-output, string manipulation, numeric elementary functions, and random number generation.” —:Ada-Europe’s Ada Reference Manual: Section 1: General See legal information