Early years Modern computers first emerged in the 1940s and 1950s. The software that they ran was naturally used to perform calculations, but it was specially designed for a substantial application that was not limited to simple calculations. For example, the
LEO computer was designed to run business application software such as
payroll. Software specifically to perform calculations as its main purpose was first written in the 1960s, and the first software package for general calculations to obtain widespread use was released in 1978. This was
VisiCalc and it was called an
interactive visible calculator, but it was actually a
spreadsheet, and these are now not normally known simply as calculators. The
Unix version released in January 1979, V7 Unix, contained a
command-line accessible calculator.
Simulation of hardware calculators Calculators have been used
since ancient times and until the advent of software they were physical, hardware machines. The most recent hardware calculators are electronic hand-held devices with buttons for digits and operations, and a small
display for inputs and results. The first software calculators imitated these hardware calculators by implementing the same functionality with mouse-operated, rather than finger-operated, buttons. Such software calculators first emerged in the 1980s as part of the original
Macintosh operating system (
System 1) and the
Windows operating system (
Windows 1.0). Some software calculators directly simulate one of the hardware calculators, by presenting an image that looks like the calculator, and by providing the same functionality.
Software calculators on the Internet As
web browsers became more powerful, developers focused more on creating online calculators rather than relying on local hardware. In May 2009,
Wolfram Research announced the first public release of
WolframAlpha. Rather than acting like a typical
search engine, the tool was described as a "computational knowledge engine" designed to compute answers from curated mathematical research data rather than listing web pages. In 2011,
Desmos was launched as a free browser-based graphic calculator at the
TechCrunch Disrupt conference held in
New York City. Founder Eli Luberoff developed the software as an alternative to hardware graphic calculators, noting that they were too expensive for most students. ==Examples==