General

• International Date Line
  International Date Line
  The International Date Line is a generally north-south imaginary line on the surface of the Earth, passing through the middle of the Pacific Ocean, that designates the place where each calendar day begins...
  
  , the time zone date boundary
• Intermediate density lipoprotein
  Intermediate density lipoprotein
  Intermediate-density lipoproteins belong to the lipoprotein particle family and are formed from the degradation of very low-density lipoproteins. IDL is one of the five major groups of lipoproteins that enable fats and cholesterol to move within the water-based solution of the bloodstream...
  
  
• John F. Kennedy International Airport
  John F. Kennedy International Airport
  John F. Kennedy International Airport is an international airport located in the borough of Queens in New York City, about southeast of Lower Manhattan. It is the busiest international air passenger gateway to the United States, handling more international traffic than any other airport in North...
  
  , from when it was named "Idlewild Airport" ("IDL" IATA airport code)
• International Drivers License
• International Darts League
  International Darts League
  The Topic International Darts League was a darts tournament held at the Triavium in Nijmegen, Netherlands. Raymond van Barneveld dominated the tournament, held in his home country, winning it on three of the five occasions it was held...
  
  , a defunct major darts tournament
• IDL Drug Stores
  IDL Drug Stores
  IDL Drug Stores or the Independent Drugstores League was a cooperative of independent drugstores that disbanded in the late 1960s. Several drugstores retain the IDL name, including Seebers IDL in Newport, Washington and Schneiders IDL in Minneapolis, Minnesota. Among their promotional items were...
  
  , a now-defunct independent drug store cooperative

Computer Science

• Interface description language
  Interface description language
  An interface description language , or IDL for short, is a specification language used to describe a software component's interface...
  
  , any computer language used to describe a software component's interface
  • IDL specification language
    IDL specification language
    IDL is a software interface description language created by William Wulf and John Nestor of Carnegie Mellon University and David Lamb of Queen's University, Canada.Like other interface description languages, IDL defined interfaces in a language- and machine- independent way, allowing...
    
    , the original IDL created by Lamb, Wulf and Nestor at Queen's University, Canada
  • OMG IDL, an IDL standardized by Object Management Group
    Object Management Group
    Object Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...
    
     and implemented in CORBA
    Çorba
    Chorba , ciorbă , shurpa , shorpo , or sorpa is one of various kinds of soup or stew found in national cuisines across Middle East...
    
     for DCE/RPC services, also selected by the W3C for exposing the DOM of XML, HTML, CSS, and SVG documents.
  • Microsoft Interface Definition Language, an extension of OMG IDL for supporting Microsoft's DCOM services
• IDL (programming language) (Interactive Data Language), a data analysis language popular for science applications
• ICAD Design Language
  ICAD
  ICAD was a Knowledge-Based Engineering system that was based upon the Lisp programming language...
  
  , a knowledge-based engineering language