Open Programming Language (OPL) is a programming language for embedded systems and mobile devices that run the operating systems EPOC and Symbian. It was released by the British company Psion in 1984. Use Originally designed for use on their classic Psion PDAs such as the Series 3, 5/5mx, Series 7, and netBook–netPad, and the Psion produced MC218, OPL was provided as part of the standard application suite. It can also be installed on the Nokia 9200, 9300 and 9500 Communicator series mobile telephone and personal digital assistant (PDA) and the Sony Ericsson P800, P900, P910 series. OPL is also included in Psion Teklogix industrial handhelds such as the Workabout mx, and it also appeared in the lesser known Oregon 'Osaris' organiser, a broadly compatible EPOC32 device that uniquely used version 4 of the OS. OPL is an interpreted language similar to BASIC. A fully Visual Basic-compatible language OVAL has been also developed. History The language was originally named Organiser Programming Language, developed by Psion Ltd for the Psion Organiser. Designed by Colly Myers with the first iteration implemented by Richard Harrison and Martin Stamp. The first implementation (without graphics) was for the original Psion Organiser (now referred to as the Psion Organiser I, 1984), and it came bundled with the Science, Finance and Math data packs. It became truly accessible as built-in software in the Psion Organiser II (1986), and the language went on to be used in the Psion Series 3 and later. After Psion retired from the personal digital assistant market, a project aiming to bring OPL to Symbian came to fruition, when the fledgling Symbian Developer Program released it as open-source software. The language is now available on SourceForge in a project named opl-dev. The language is currently unavailable for Symbian OS v8 and later. With the subsequent retirement of the Symbian OS, it seems unlikely OPL will be made available for later generations of Symbian devices. As of 2010, Nokia device developers were encouraged to use Python for S60 instead (See Python for S60). Examples Here is the console version of a "Hello, World!" program: PROC main: PRINT "Hello World!" PAUSE 40 ENDP (Source code taken from the PCDevPrimer in the OPL Wiki.) And here is a GUI version for Nokia's Series 80 user interface: CONST KKeyEnter%=13 PROC hello: dINIT "Hello" dTEXT "","Hello World!" dBUTTONS "OK",KKeyEnter% DIALOG ENDP OPL is a structured programming language. OPL programs