LINC 4GL
| Company type | Software |
|---|---|
| Industry | Computer software |
| Founded | January 1, 1980 |
| Founder | Gil Simpson, Peter Hoskins |
| Products | Fourth-generation programming language, LINC Development Environment (LDE), LINC Development Assistant (LDA), Unisys Enterprise Application Environment (EAE), Unisys Agile Business Suite (AB Suite) |
| Owner | Unisys |
| Website | www |
LINC (short for "Logic and Information Network Compiler") is a fourth-generation programming language chiefly utilized on Unisys computer platforms.
Background
Conceived by two developers, LINC was created as a framework to streamline application development for organizations sharing similar operational structures. These enterprises managed entities such as "commodities," "parts," "suppliers," or "customers"—referred to as "components" within LINC—and engaged in processes like manufacturing, assembling, procurement, or sales, termed "events."
The combination of these components and events formed the foundation for the application's database, user interfaces, and business logic—collectively known as "interface specifications" or "ispecs."
Included within LINC was LIRC (Logic and Information Report Compiler), a module designed to produce reports such as purchase orders and invoices based on user-defined perspectives called "profiles." These reports could be executed as background jobs, enhancing operational workflow.
The language employed unique terminology—for instance, DO.WHEN instead of IF or LOOP—to abstract technical complexity and simplify coding. A major strength of LINC was its comprehensive integration with Burroughs system features: including the operating system, job control language, COBOL, database management, network configurations, and terminal interfaces.
Starting with version 11, LINC transitioned from managing source-code files to storing specifications within a database governed by the LINC Development Environment (LDE), which improved validation processes and system definitions through terminal screen design tools.
In the early 1990s, the introduction of the PC-based LINC Development Assistant (LDA) allowed specification creation using Smalltalk and C++. From version 17 onward, all development activities were consolidated within LDA.
Now referred to as Unisys Enterprise Application Environment (EAE), LINC compiles executable COBOL code targeting Unisys ClearPath systems (Dorado and Libra), as well as Microsoft Windows, Unix, and Linux platforms. It generates graphical user interfaces in
and supports various databases including Burroughs DMSII, Sperry RDMS, Oracle database, and Microsoft SQL Server.
Recent Update:
The Unisys EAE platform has evolved into Unisys Agile Business Suite (AB Suite), which enhances LDL by introducing LDL+ with object-oriented capabilities. This development environment integrates seamlessly with Microsoft Visual Studio IDE and Team Foundation Server 2012. It utilizes a UML-based Class Diagram that facilitates round-trip synchronization between business rules and source code.
Version 4.0 of AB Suite enables deployment across both .NET and ClearPath MCP environments. Its transparent code generation accelerates application design and rollout by automatically detecting database modifications and migrating data models without requiring developer intervention.
A notable benefit of AB Suite is its ability to perform rapid Function Point analysis, supporting concurrent development efforts that effectively reduce backlog volumes.
History
Originating in the early 1980s through the efforts of New Zealand programmers Gil Simpson and Peter Hoskins during their tenure in Saudi Arabia, LINC was initially crafted for a specific Burroughs platform. It integrated:
- B1000 hardware,
- MCP operating system,
- COBOL applications,
- WFL job control,
- DMS II database,
- NDL,
- MT983/ET1100 CRT terminals.
LINC generated third-generation source code including COBOL, DMSII, NDLII, and WFL components. Its job control system compiled these elements into a cohesive database-driven application with user terminal support.
In 1982, Burroughs secured sales rights while development remained with the original creators. The product's scope expanded to support Burroughs mid-range and large-scale systems. Following the merger of Burroughs with Sperry Corporation forming Unisys, LINC was adapted to operate on Sperry's UNIVAC 1100/2200 series hardware.
A development center was established in Christchurch, New Zealand by Gil Simpson, later transferring ownership to Unisys. Mainframe resources were relocated to Unisys' ACUS ("Australian Centre for Unisys Software") facility in Sydney. Subsequently, Simpson's team developed the Jade language/database platform capable of importing and executing LINC code on standard hardware.
LINC received support across multiple environments including:
- ClearPath A-Series,
- ClearPath 2200,
- Unix SUN Solaris,
- Unix IBM RS6000,
- Unix HP9000,
- Unix Sequent,
- Unixware,
- Windows Server.
In 2008, development responsibilities transitioned from ACUS to an offshore outsourcing operation in India. Over time, the product has been deployed by more than 4,000 organizations globally.
Strengths
- User-friendly interface that streamlines programming with Burroughs DMS and COBOL.
- Updated to support various platforms, facilitating system and database migrations.
- Consolidates design specifications within a unified database framework.
- Guarantees that the produced code accurately reflects the original design requirements:
- Client interfaces remain uniform with concurrently generated systems.
- Database access routines correspond exactly to the database schema.
Weaknesses
LINC faces challenges competing against a wide array of turnkey solutions offered by other vendors, particularly IBM. Acquiring and adapting established software packages (such as the Hogan retail banking system) is frequently viewed as more cost-effective and less risky than developing an entire business application from the ground up using LINC.
Additional limitations arise due to its dependence on Burroughs DMS and COBOL, which differ considerably from other environments:
- Developers accustomed to Unix or Windows platforms may encounter difficulties adapting to its approach.
- The necessity to maintain cross-platform compatibility restricts the utilization of advanced Oracle features or queries that are not supported on mainframe systems.
External links
- Information Exchange Group, supplier of tools for LINC development: http://www.ieg-inc.com/