Assembly languages

Originally, machine code was the first and only way to program computers. Assembly language was the next type of language used; thus, is one of the oldest families of computer languages in use today. Many dialects and implementations are available, usually some for each computer processor architecture. It is very basic and termed a low-level programming language. It is one of the more difficult languages to work with being untyped and rigid. Several simplified dialects exist for education.

Low-level languages must be written for a specific processor architecture and cannot be written or taught in isolation without referencing the processor for which it was written. Unlike higher-level languages, using an educational assembly language needs a representation of a processor, whether virtualized or physical. Assembly is used for learning about fundamental computer processor operation.

• Little Man Computer (LMC) is an instructional model of a simple von Neumann architecture computer with all the basic features of modern computers. It can be programmed in machine code (usually decimal) or assembly. It is based on the concept of having a little man locked in a small room. At one end of the room are 100 mailboxes as memory; each can hold a three-digit instruction or data. At the other end of the room are two mailboxes labeled INBOX and OUTBOX which receive and emit data. In the middle of the room is a work area with a simple two-function (add and subtract) calculator called the Accumulator and a resettable counter called the Program Counter. The counter is similar to what a doorperson uses to count how many people have entered a facility; it can count up 1 or can be reset to 0. As specified by the von Neumann architecture, memory holds both instructions and data. The user loads data into the mailboxes and then signals the little man to begin executing.
• Next Byte Codes (NBC) is a simple language with assembly language syntax that is used to program Lego Mindstorms NXT programmable bricks. The command line compiler emits NXT-compatible machine code and supports Windows, Mac OS X and Linux.
• Little Computer 3 (LC-3), is an assembly language with a simplified instruction set, but can be used to write moderately complex assembly programs and is a theoretically viable target for C compilers. It is simpler than x86 assembly but has many features similar to those in more complex languages. These features make it useful for teaching basic programming and computer architecture to beginning college computer science, and computer engineering students, which is its most common use.
• DLX is a reduced instruction set computer (RISC) processor architecture by the main designers of the MIPS and the Berkeley RISC designs, two benchmark examples of RISC design. DLX is essentially a cleaned-up, simplified MIPS, with a simple 32-bit load/store architecture. It is widely used in college-level computer architecture courses.
• MIX and MMIX are hypothetical computers used in Donald Knuth's monograph, The Art of Computer Programming (TAOCP). The MIX computer systems are designed to educate individuals about what goes inside a computer through its use of a basic and comprehensible machine language. Despite its simplicity, the MIX system handles complex tasks that are found in typical high-performance general-purpose computers. MIX is a hybrid programmable in binary and decimal numbers; most programs written for it will work using either form. Software implementations for MIX and MMIX have been developed by Knuth and made freely available. Several versions of both emulators exist. MIX is a 1960s-style computer. It is superseded by MMIX, a newer modern computer architecture, a 64-bit RISC instruction set architecture (ISA). For MMIX, Knuth collaborated with the architects of the MIPS and Alpha ISAs.

BASIC variants

BASIC (which stands for Beginner's All-purpose Symbolic Instruction Code) was invented in 1964 to provide computer access to non-science students. It became popular on minicomputers during the 1960s and became a standard computing language for microcomputers during the late 1970s and early 1980s. The goals of BASIC were focused on the need of learning to program easily:

• be easy for beginners to use,
• be interactive,
• provide clear and friendly error messages,
• respond quickly, and
• do not require an understanding of computer hardware or operating systems.

What made BASIC particularly useful for education was the small size of programs that could illustrate a concept in a dozen lines. BASIC continues to this day to be frequently self-taught with excellent tutorials and implementations.

See also List of BASIC dialects by platform.

BASIC offers a learning path from learning-oriented BASICs such as Microsoft Small Basic, BASIC-256 and SiMPLE, to more full-featured BASICs like Visual Basic .NET and Gambas.

• Microsoft Small Basic is a restricted version of Visual Basic designed as a first language, "aimed at bringing 'fun' back to programming". The language is explicitly quite small with only 15 intuitive keywords. By including object-specific libraries for things of general interest to children, children can create entertaining, interactive programs, on the net or on the desktop. For example, with 6 lines of code, it is possible to demonstrate a random network image viewer using Flickr as the source.^[1] The system utilizes the Microsoft Visual Studio IDE to provide auto-completion and context-sensitive help.
• Basic-256 an easy-to-use version of BASIC designed to teach anybody the basics of computer programming. It uses traditional BASIC control structures (gosub, for loops, goto) for ease of understanding program flow control. It has a built-in graphics mode that allows children to draw pictures on the screen after minutes.
• SiMPLE is a programming development system that was created to provide easy programming abilities for everybody, especially non-professionals. It is somewhat like AppleSoft BASIC. It is compiled and lets users make their own libraries of often-used functions. "Simple" is a generic term for three slightly different versions of the language: Micro-SIMPLE (uses only 4 keywords), Pro-SiMPLE, and Ultra-SiMPLE (using 23 keywords).
• Hot Soup Processor is a BASIC-derived language used in Japanese schools.
• TI-BASIC is a simple BASIC-like language implemented in Texas Instruments graphing calculators, often serving as a student's first look at programming.
• SmallBASIC is a fast and easy-to-learn BASIC language interpreter ideal for everyday calculations, scripts and prototypes. It includes trigonometric, matrix, and algebra functions, a built in IDE, a powerful string library, system, sound, and graphic commands, and a structured programming syntax.

C based

• Ch is a C/C++ interpreter designed to help non-CS students to learn math, computing and programming in C and C++. It extends C with numerical, 2D/3D graphical plotting and scripting features.

Java-based

• NetLogo, written in Java and Scala, is a development environment for building and exploring scientific models, specifically agent-based models. It is in widespread use both in science research (Science papers using NetLogo) and in educational contexts, including elementary, secondary schools, universities and museums.

Lisp-based

Lisp is the second oldest family of programming languages in use today, and as such has many dialects and implementations with a wide range of difficulties. Lisp was originally created as a practical mathematical notation for computer programs, based on lambda calculus, which makes it particularly well suited for teaching theories of computing. As one of the earliest languages, Lisp pioneered many ideas in computer science, including tree data structures, automatic storage management, dynamic typing, object-oriented programming, and the self-hosting compiler all of which are useful for learning computer science.

The name LISP derives from "LISt Processing language". Linked lists are one of the languages' major data structures, and Lisp source code is made of lists. Thus, Lisp programs can manipulate source code as a data structure, giving rise to the macro systems that allow programmers to create new syntax or even new domain-specific languages embedded in Lisp. Therefore, Lisps are useful for learning language design and creating custom languages.

A reasonable learning path would be Logo followed by any educational variant such as Scheme or newLISP, followed by a professional variant such as Common Lisp.

• Logo is a language that was specifically designed to introduce children to programming. The first part of learning Logo deals with "turtle graphics" (derived from turtle robots) used as early as 1969 with proto-Logo. In modern implementations, an abstract drawing device, called the turtle, is used to make programming for children very attractive by concentrating on doing turtle graphics. Seymour Papert, one of the creators of Logo, was a major thinker in constructionism, a variety of constructivist learning theories. Papert argued that activities like writing would naturally be learned by much younger children provided that they adopted a computing culture.^[2] Logo was thus designed not only to teach programming, and computing concepts, but to enhance a child's entire well-being in a culture increasingly dominated by technology, "more important than having an early start on intellectual building, is being saved from a long period of dependency during which one learns to think of learning as something that has to be dished out by a more powerful other...Such children would not define themselves or allow society to define them as intellectually helpless."^[2] It has been used by children as young as 3 years old and has a track record of 30 years of success in education. Since Logo is actually a streamlined version of Lisp with more advanced students, it can be used to introduce the basic concepts of computer science and even artificial intelligence. Logo is widely available on virtually every platform, in both free and commercial versions.

Scala-based

• Kojo is an interactive desktop development environment developed primarily for educational purposes application that runs on Windows, Linux, and OS X. It is a learning environment, with many different features that help with the exploration, learning, and teaching of concepts in the areas of computer programming and critical thinking, math and science, art, music, and creative thinking, computer and internet literacy.^[3]

Smalltalk-based

As part of the One Laptop per Child project, a sequence of Smalltalk-based languages has been developed, each designed to act as an introduction to the next. The structure is Scratch to Etoys to Squeak to any Smalltalk.^[4] Each provides graphical environments which may be used to teach not only programming concepts to kids but also physics and mathematics simulations, story-telling exercises, etc., through the use of constructive learning. Smalltalk and Squeak have fully featured application development languages that have been around and well respected for decades; Scratch is a children's learning tool.

• Scratch is a visual language based on and implemented in Squeak. It has the goal of teaching programming concepts to children and letting them create games, videos, and music. In Scratch, all the interactive objects, graphics, and sounds can be easily imported to a new program and combined in new ways. That way, beginners can get quick results and be motivated to try further. The Scratch community has developed and uploaded over 3,000,000 projects.^[5] It is developed by the Lifelong Kindergarten group at MIT Media Lab.
• Etoys is based on the idea of programmable virtual entities behaving on the computer screen. Etoys provides a media-rich authoring environment with a simple, powerful scripted object model for many kinds of objects created by end-users. It includes 2D and 3D graphics, images, text, particles, presentations, web pages, videos, sound and MIDI, the ability to share desktops with other Etoy users in real-time, so many forms of immersive mentoring and play can be done over the Internet. It is multilingual and has been used successfully in United States, Europe, South America, Japan, Korea, India, Nepal, and elsewhere. The program is aimed at children between the ages of 9-12.^[6]

• Squeak is a modern, open-source, full-featured implementation of the Smalltalk language and environment. Smalltalk is an object-oriented, dynamically typed, reflective language created to underpin the "new world" of computing exemplified by "human-computer symbiosis".^[7] Like Lisp, it has image-based persistence, so everything is modifiable from within the language itself (see Smalltalk#Reflection).^[8] It has greatly influenced the industry introducing many of the concepts in object-oriented programming and just-in-time compilation. Squeak is the vehicle for a wide range of projects including multimedia applications, educational platforms and commercial web application development. Squeak is designed to be highly portable and easy to debug, analyze, and change, as its virtual machine is written fully in Smalltalk.

Pascal

• Pascal is the most well-known language that was designed with education in mind. From the late 1970s to the late 1980s, it was the primary choice in introductory computer science classes for teaching students programming in both the US and Europe. Its use for real-world applications has since increased, and regarding it as a purely educational language has since become somewhat controversial.

Other

• CircuitPython is a beginner-oriented version of Python for interactive electronics and education.
• Rapira is an ALGOL-like procedural programming language, with a simple interactive development environment, developed in the Soviet Union to teach programming in schools.
• Src:Card is a tactile offline programming language embedded in an educational card game.