Symbian OS is an operating system with associated libraries, user interface frameworks and information implementations of most common information, by Symbian Ltd.. These are the descendent of Psion's EPOC.

Symbian is presently owned by Ericsson, Panasonic, Nokia, Samsung, Siemens AG and Sony Ericsson.

Design
There are multiple user interface flavours that use a Symbian OS, like Sony Ericsson's UIQ and Nokia's (Series 60, Series 80, etc). A adaptability of a interface enables the utilise of Symbian OS in various form-factors of hand-handheld equipment: clam-eggshell or even tablet, keyboard and/or pen, PDA or mobile phones, and others.

Symbian OS, using its roots inside Psion Software's EPOC (which itself had similarities to the internals of VMS, a grown-fully grown POSIX compatible operating system for mini-computers in the Eighties) is structured prefer numerous desktop operating systems, by owning pre-emptive multitasking, multithreading, and memory protection.

Symbian OS's major even benefit is the fact that it was built for handheld equipment, sustaining limited resources, that can be run months or years. There is a hard emphasis in conserving memory, utilizing Symbian-specific programming idioms like descriptors and a cleanup stack. Together using more techniques, these keep memory usage on line & memory leaks rare. There come similar techniques for conserving disc space (though a disks in Symbian equipment are normally flash memory). What is more, completely Symbian OS programming is event-depending, & a CPU is switched off when applications are non directly treating by owning an event. This is achieved across the programming idiom known as active objects. While forgoing utilizing these techniques properly, an application might get into down the battery of the phone within only a few hours; by using the babies, the battery lives for a week.

Everthing of this makes Symbian OS's flavour of C++ very specialised, with the steep learning curve. Notwithstanding, numerous Symbian OS hardware can too exist as programmed within OPL, Python, Visual Basic, Simkin, and Perl - together with a J2ME and Personal Java flavours of Java.

Competition
Symbian OS competes by owning more upwardly mobile operating systems, like Windows Mobile, Palm OS, and Linux. It likewise competes using a embedded operating systems utilized in lower-prevent phones, like NOS and OSE, which tend to be maintained per phone service themselves. Symbian OS' major benefit across these embedded operating systems is its modularity - there exists runtime linking between DLLs circuit board the device, & an emphasis on plug-in architectures. This makes complex phones quickly to have, though this is every now & agaaround offset per complexness of Symbian OS C++ and a awkwardness of attend an additional company for an OS (instead of sleep with in-home).

A benefits on top more 'open' OS challenger (like Linux and Windows Mobile, a survive 1 is non Open Source) are other debatable. Phone vender & network operators prefer a customisability of Symbian OS relative to Windows. This customisability, though, makes desegregation the Symbian OS phone additional hard. It's imaginable that Linux goes as well far in a more counsel, & is only as well protective to produce the phone from either at the moment. Symbian OS's ground-higher project for upwardly mobile equipment should produce it additional power- & memory-effective, too when existence flexible.

Structure
At its last-place level sit a "base" components of Symbian OS. This includes a kernel (EKA1 or EKA2 - view a 'History' division), along by using a user library which allows user-side applications to asking items of the kernel. Symbian OS has the microkernel architecture, which means that a minimum necessary is inside the kernel. It does contain the scheduler and memory management, but there are no networking or even filesystem trend lines. These items come provided by user-side servers. a base layer includes the file server, which will bring a fairly DOS-prefer learn from of the filesystems on the device (from each one cause hwhen a cause letter, & backslashes come utilized as the directory delimeter).

Immediately above base come the choice of "system libraries". These choose the lot shapes & sizes, including e.g. character placed conversion, a DBMS database, & resource file treating.

Farther higher, the software package is non thus readily intended into a fold.

There is a big "networking and communication" subsystem, which has trinity independent servers - ETEL (EPOC telephony), ESOCK (EPOC sockets) & C32 (responsible serial communication). Every one has the plug-circuit card scheme. For instance ESOCK allows different ".PRT" protocol modules, implementing different types of networking protocol scheme. There's lots of stuff on to short-range communication links as well, like Bluetooth, IrDA and USB.

There's likewise the big total of "user interface" code. Potentially though a interface themselves come maintained by more parties, a base classes & substructure ("UIKON") for completely UIs come present around Symbian OS.

There are besides the choice of "application engines" for popular smartphone applications like calendars, location books, & project lists. a average Symbian OS application is split higher into an engine DLL & the in writing application - the application existence a thinly wrapper all over the engine DLL. Symbian OS will bring occasionally one engine DLLs.

There are, course, numbers of more items that don't healthy into this model - for instance, SyncML, J2ME providing another placed of APIs in top of virtually all of the OS & multimedia. Quite an few one items come frameworks, & marketer come required to supply plug-card to these frameworks from either third parties (for instance, Packet Video for multimedia codecs). This has the benefit that a APIs to such areas of functionality come a equivalent in numbers of phone system, & that trafficker become much of flexibility, however means that phone marketer require to clean much of integration operate to produce a Symbian OS phone.

History
Inside 1980, Psion Software was founded by David Potter.

EPOC16. Psion freed many Series 3 devices from 1991 to 1998 which utilized a EPOC16 OS, as well referred to as SIBO.

EPOC OS Releases 1–3. A Series 5 device, released inside 1997, utilized a foremost iterations of the EPOC32 OS.

EPOC Release Four. Oregon Osaris and Geofox 1 were freed applying ER4.

Around 1998, Symbian Ltd. is formed as a partnership between Ericsson, Nokia, Motorola and Psion, to explore the convergence between PDAs and mobile phones.

EPOC Release Fin. Series 5mx, Series 7, Revo, netBook, netPad, Ericsson MC218, and a Ericsson R380 were freed inside 1999 applying ER5.

ER5U. U = Unicode. A number one phone, a Ericsson R380 was freed utilizing ER5U around 2000. It was does'nt an 'open' phone - programs may not become installed.

Symbian OS v6.Cipher & v6.Ace. Occasionally known as ER6. A 1st 'open' Symbian OS phone, a Nokia 9210, was freed in Hexad.Cypher.

Symbian OS v7.Cypher & v7.0s. Foremost shipped within 2003.

Inside 2004, Psion sold its stake inside Symbian.

Too inside 2004, the number 1 worm for mobile phones utilizing Symbian OS, Cabir, was developed, which used Bluetooth to spread itself to nearby phones. Look at Cabir and Symbian OS threats.

Symbian OS v8.Zero. Number 1 shipped around 2004, one of its benefits would own been the guide of deuce different kernels (EKA1 or even EKA2). Nevertheless, a EKA2 kernel version did does'nt ship until SymbianOS v8.1b. A kernels behave close to identically from either user-side, however come internally super different. EKA1 was chosen by the bit of manufacturers to maintain compatibility sustaining old driver, when EKA2 offered benefits like a firm real-instance capability.

Symbian OS v8.Ace. Au fond the filtered-higher version of Eighter.Cypher, this was available within Octonary.1a & Octonary.1b versions, by having EKA1 & EKA2 kernels severally. A Octet.1b version, using EKA2's lone-chip phone trend lines however there are no extra security layer, was popular among Japanese phone service desiring a realtime trend lines but not allowing for open application installation.

Symbian OS v9.Cipher. This version was utilized for internal Symbian purposes single. It was deproductized inside 2004.

Symbian OS v9.One. Early around 2005, a newly version of Symbian was announced. Improvements in the OS mean that applications & content, & so the developers investment, come better secure than ever. A fresh ARM EABI binary model means developers want to retool & a security changes mean it can use to recode. A Nokia N91 might probably exist as a 1st SymbianOS 9.One device on the market.

Symbian OS has typically maintained sensible binary compatibility. Inside theory a OS was BC from either either ER1-ER5, so from Captain hicks.0 to 8.1b. Material changes were required for Niner.Cipher, related to information & security, however this should exist as the of these-off event. A move from either requiring ARMv4 to requiring ARMv5 did non break backwards compatibility.

Devices that have used the Symbian OS
Ericsson R380 (2000) was the number 1 commercially available smartphone according to Symbian OS Nokia 9210 Communicator smartphone (32-bit 66Mhz ARM9-based RISC CPU) (2001), 9300 Communicator (2004), 9500 Communicator (2004) using the Nokia Series 80 interface Sony Ericsson P800 (2002), P900 (2003), P910 (2004), Motorola A920, A925, A1000, DoCoMo M1000, BenQ P30, P31 using the UIQ user interface. Nokia Series 60 (2002) Nokia Series 60 is utilized inside various phones, a number one existence a Nokia 7650, then a Nokia 3650, followed by the Nokia 3620/3660, Nokia 6600 and Nokia 7610. A Nokia N-Gage and Nokia N-Gage QD gaming/smartphone combos come as well Series 60 platform equipment. It was besides utilized in more manufacturers' phones like a Siemens SX1 and Sendo X. Recent, other advanced hardware utilizing Series 60 include a Nokia 6630, the Nokia 6680 and a next generatioNorth N series, including a Nokia N90 and Nokia N91. Nokia 7710 (2004) using the Nokia Series 90 interface. Fujitsu & Mitsubishi phones for NTT DoCoMo in Japan, using an interface developed specifically for a babies typically known as FOMA fallowing the DoCoMo "Freedom of Mobile Access" network brand.

Developing on Symbian OS
Getting in Symbian OS may ab initio pop up confusing, when no individual SDK available for download from Symbian. Instead, there are SDKs available for both of the independent user interface families: UIQ, Series 60, and then-shortly. Single phone products, or even families, typically use SDKs downloadable from either a manufacturer's web site as well. the SDKs contain documentation, a header files & library files called upon to build Symbian OS computer software, & a Windows-depending ape ("WINS"). Higher until version Eighter, the SDKs as well involved a version of the GCC compiler (a cross-compiler) required to build software package to operate on the device. Symbian OS 9 utilizes the fresh ABI and so requires the newly compiler - the selection of compilers come available including the fresh version of GCC (watch external links in the image below). The commercial message Windows IDE has always been expected to build for the WINS emulator - historically, this was Visual Studio but for recent versions of Symbian OS, CodeWarrior is favoured. At present that you too keep around SuperWaba, which can be utilized to build Symbian 7 & 7s software using the Java language.