computer science

NCSA HTTPd

NCSA HTTPd is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand NCSA HTTPd rather than just read about it. In short: NCSA HTTPd is a discontinued web server originally developed at the NCSA at the University of Illinois at Urbana–Champaign by Robert McCool and others. First released in 1993, it was among the earliest web servers developed, following Tim Berners-Lee's CERN httpd, Tony Sanders' Plexus server, and some others.

Key takeaways

NCSA HTTPd belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NCSA HTTPd to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NCSA HTTPd from memory before moving on to harder problems.

Reference excerpt

NCSA HTTPd is a discontinued web server originally developed at the NCSA at the University of Illinois at Urbana–Champaign by Robert McCool and others. First released in 1993, it was among the earliest web servers developed, following Tim Berners-Lee's CERN httpd, Tony Sanders' Plexus server, and some others. It was for some time the server counterpart to NCSA Mosaic. It also introduced the Common Gateway Interface, allowing for the creation of dynamic websites. After Robert McCool left NCSA in mid-1994, the development of NCSA HTTPd slowed greatly. An independent effort, the Apache project, took the codebase and continued; meanwhile, NCSA released one more version (1.5), then ceased development. In August 1995, NCSA HTTPd powered most of all web servers on the Internet; nearly all of them quickly switched over to Apache. By April 1996, Apache passed NCSA HTTPd as the No. 1 server on the Internet, and retained that position until mid-to-late 2016.

See also Comparison of web server software National Center for Supercomputing Applications

References

External links Official website at the Wayback Machine (archived 1997-12-10)

Illustrations

Worked examples

Example 1 — a first encounter with NCSA HTTPd

Start with the simplest possible case. Write down what NCSA HTTPd claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to NCSA HTTPd before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about NCSA HTTPd ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of NCSA HTTPd

In research: NCSA HTTPd appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses NCSA HTTPd in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: NCSA HTTPd is common in secondary-school and first-year university syllabi. It links to neighbouring topics Free web server software, Internet stubs, Network software stubs, so understanding it makes those chapters shorter.
In everyday life: Look for NCSA HTTPd outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study NCSA HTTPd in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NCSA HTTPd means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain NCSA HTTPd out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NCSA HTTPd in simple terms?

Why does NCSA HTTPd matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study NCSA HTTPd?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on NCSA HTTPd.