# Sailfish OS

Sailfish OS is a paid Linux-based operating system based on free software, and open source projects such as Mer as well as including a closed source UI. The project is being developed by the Finnish company Jolla.
The OS first shipped with the original Jolla Phone in 2013; while its sale stopped in 2016, it was supplied with software updates until the end of 2020. It also shipped with Jolla Tablet in 2015 and from other vendors licensing the OS. The OS is ported by community enthusiasts to third-party mobile devices including smartphones and tablet computers. Sailfish OS can be used for many kinds of devices.

## History and development

The OS is an evolved continuation of the Linux MeeGo OS previously developed by alliance of Nokia and Intel which itself relies on combined Maemo and Moblin. The MeeGo legacy is contained in the Mer core in about 80% of its code; the Mer name thus expands to MEego Reconstructed. This base is extended by Jolla with a custom user interface and default applications. Jolla and MERproject.org follow a meritocratic system to avoid the mistakes that led to the MeeGo project's then-unanticipated discontinuation.
The main elements for Sailfish OS 2.0 include:
* Technically stronger OS core
* Improved Android application compatibility
* Support for ARM and Intel architectures, including the Intel Atom x3 processor, or any platform with kernel useable (settle-able) for MER core stack (also called middleware of Sailfish).
* Design to provide visibility in the UI for digital content providers and to enable OS level integration for mobile commerce
* Strong multitasking (one of the most important advantage of the OS and declared to be the best one on the market)
* Strong personalization features
* Enhanced user interface with new UI/UX features, including simpler swipe access to main functions, enhanced notifications and events views.

## Software architecture

The Sailfish OS and the Sailfish software development kit (SDK) are based on the Linux kernel and Mer. Sailfish OS includes a multi-tasking graphical shell called "Lipstick" built with Qt by Jolla on top of the Wayland display server protocol. Jolla uses free and open-source graphics device drivers but the Hybris library allows use of proprietary drivers for Android. Jolla fuzzily stated in 2015 that their goal for Sailfish is to become open source eventually, but some key components of Sailfish OS have been licensed proprietary by Jolla from the start and ever since (as of Sailfish OS 4.5.0.24 in September 2023).
Sailfish OS can run some Android applications through a proprietary compatibility layer.

### Targeted device classes

Sailfish is targeted at mobile devices. Since it inherited around 80% of MeeGo code, Sailfish can be used as a complete general-purpose Linux OS on devices including in vehicle infotainment (IVI), navigation, smart TV, desktops and notebooks, yachts, automotive, e-commerce, home appliances, measuring and control equipment, smart building equipment, etc. See use cases of original MeeGo to compare, and the Devices section for devices that run the Sailfish OS.

### Sailfish OS SDK

The Sailfish OS SDK was announced at the Slush Helsinki conference in 2012, and the alpha was published in February 2013. The SDK, installation and coding tutorials are available for free download from the Sailfish OS website despite the overall license not being open source.
Sailfish SDK uses Qt with VirtualBox for development, compiling and emulation purposes, in contrast to the simulation method. This technique allows compilation on the Sailfish OS and full testing of developed software in the virtual machine, emulating – not simulating – the whole Sailfish OS. This also separates development activities and side effects from everything else running on the host computer, leaving it undisturbed by developments and tests. According to Jolla, development with Sailfish SDK is development on Sailfish OS itself; there are no differences between developed software appearance and behaviour in the SDK and on a device running Sailfish OS.
The availability of source code to the SDK allows shaping and rebuilding to companies' or developers' specific needs, creating a context-specific environment that is set once and needs no preparation when the device is booted. The SDK runs on the operating systems Android, 32- and 64-bit versions of Linux, 64-bit versions of OS X, and Microsoft Windows. It can be used for compiling software for Sailfish OS devices from Linux sources. Its general console/terminal mode follows a commonly used standard. Compatible binaries or libraries can also be used.

### Application programming interfaces

Sailfish OS uses open source Qt APIs (Qt 5, QtQuick 2 etc.) and a proprietary Sailfish Silica for the UI. Standard Linux APIs are provided by the Mer Core.
Sailfish, Ubuntu and Plasma Active have been cooperating to share common APIs. When successful, this will make the platforms compatible on the API level.
Sailfish Browser is the default web browser based on Gecko and using embedlite (also known as IPCLiteAPI), a lite-weight embedding API from Mozilla. Uses proprietary components.

## Software overview
### UI supported human languages

Officially Jolla declares supporting the following 14 languages for the user interface: Danish, German, English (UK), Spanish, French, Italian, Norwegian, Polish, Portuguese, Finnish, Swedish, Russian, Chinese (mainland), and Chinese (Hong Kong). For each of them, the OS has a dedicated keyboard. There are a few more languages which are unofficially supported by community freelancers not under control by Jolla, hence more than 20 languages are supported in total. Additional languages can be installed by skilled users due to the Linux architecture.

### Public "Early access" for beta testers and developers

After positive experiences with pushing early updates to a small group of opt-in users for Sailfish Update 9 and for the connectivity hotfix, Jolla has allowed all interested parties to try a new version of Sailfish OS about 1–2 weeks before official release, in a program called "Early access". It is expected to be useful for developers and technically minded users, and a step towards more community integration into the Sailfish release process, including improvement of quality by identifying critical issues which only show up in certain environments or device setups, before rolling the update out to the wider user audience. As an added bonus, it provides a window for developers to test their applications on new releases of Sailfish OS.
In the long term it will help Jolla to establish a developer program with early release candidate access for registered developers, and to have more community involvement in platform development. The first detail Jolla is hoping to learn from this is how it can gather feedback from a large audience in a reasonable way.
Basic details about the early access update:
* The early release access is meant primarily for advanced users and developers.
* To sign up for the program there is a checkbox in the Jolla accounts profile page.
* Installed early-access release cannot be downgraded. The only way to downgrade from early access releases is to do a factory reset after removing the sign up check from the user's account profile.
* Early access releases should be considered "reasonably stable". Issues found during that period will either be fixed, or added to "known issues" on the release notes.
* Signing up for the early access releases will not void warranty.

### Version history

Sailfish OS has three naming conventions: version number, update number and version name.
* Sailfish OS 1.0 versions were named after Finnish lakes.
* Sailfish OS 2.0 supports the Jolla Tablet with x86 platforms and featured a reworked touch based UI. Releases were named after Finnish rivers.
* Sailfish OS 3.0 and 4.0 features a slightly reworked UI. Releases are named after Finnish national parks.
* Sailfish OS 4.1, 4.2, 4.3, 4.4 and 4.5 features 64 bit support on the Sony Xperia 10 II, plus a new sharing system. Releases are named after Finnish Unesco world heritage sites.
| Software version | Initial release date | Name |
| v0.99.5 | 13 November 2013 | Haaganlampi (only for subscribed developers) |
| v0.99.6 | 11 November 2013 | Idörpottarna (only for subscribed developers) |
| v1.0.0 | 16 November 2013 | Kaajanlampi (initial public release) |
| v1.0.1 | 2 December 2013 | Laadunjärvi ("Update 1") |
| v1.0.2 | 27 December 2013 | Maadajärvi ("Update 2") |
| v1.0.3 | 27 January 2014 | Naamankajärvi ("Update 3") |
| v1.0.4 | 11 March 2014 | Ohijärvi ("Update 4") |
| v1.0.5 | 7 April 2014 | Paarlampi ("Update 5") |
| v1.0.6 | Not released | Raatejärvi ("Update 6"), was merged into v1.0.7 |
| v1.0.7 | 3 June 2014 | Saapunki ("Update 7") |
| v1.0.8 | 3 July 2014 | Tahkalampi ("Update 8") |
| v1.1.0 | 16 September 2014 | Uitukka ("Update 9"), was labelled as "opt-in upgrade" |
| v1.1.1 | 14 December 2014 | Vaarainjärvi ("Update 10") |
| v1.1.2 | 1 February 2015 | Yliaavanlampi ("Update 11") |
| v1.1.3 | Not released | Åkanttrasket ("Update 12"), was merged into v1.1.4 |
| v1.1.4 | 24 March 2015 | Äijänpäivänjärvi ("Update 13") |
| v1.1.5 | Not released | Österviken ("Update 14"), was dropped at release candidate stage |
| v1.1.6 | 27 May 2015 | Aaslakkajärvi ("Update 15") |
| v1.1.7 | 24 June 2015 | Björnträsket ("Update 16") |
| v1.1.9 | 18 August 2015 | Eineheminlampi ("Update 17") |
| v2.0.0 | 19 October 2015 | Saimaa ("Update 18") |
| v2.0.1 | 12 January 2016 | Taalojärvi ("Update 19") |
| v2.0.2 | 13 May 2016 | Aurajoki ("Update 20") |
| v2.0.3 | 6 July 2016 | Espoonjoki ("Update 21"), OS version solely for the Turing Phone |
| v2.0.4 | 4 November 2016 | Fiskarsinjoki ("Update 22") |
| v2.0.5 | 14 December 2016 | Haapajoki ("Update 23") |
| v2.1.0 | 3 February 2017 | Iijoki ("Update 24") |
| v2.1.1 | 15 May 2017 | Jämsänjoki |
| v2.1.2 | 20 September 2017 | Kiiminkijoki |
| v2.1.3 | 6 October 2017 | Kymijoki |
| v2.1.4 | 12 February 2018 | Lapuanjoki |
| v2.2.0 | 30 May 2018 | Mouhijoki |
| v2.2.1 | 31 August 2018 | Nurmonjoki |
| v3.0.0 | 29 October 2018 | Lemmenjoki |
| v3.0.1 | 2 January 2019 | Sipoonkorpi |
| v3.0.2 | 13 March 2019 | Oulanka |
| v3.0.3 | 23 April 2019 | Hossa |
| v3.1.0 | 15 July 2019 | Seitseminen |
| v3.2.0 | 24 October 2019 | Torronsuo |
| v3.2.1 | 5 December 2019 | Nuuksio |
| v3.3.0 | 1 April 2020 | Rokua |
| v3.4.0 | 22 September 2020 | Pallas-Yllästunturi (the final release for the Jolla Phone) |
| v4.0.1 | 3 February 2021 | Koli |
| v4.1.0 | 10 May 2021 | Kvarken |
| v4.2.0 | 25 August 2021 | Verla |
| v4.3.0 | 28 October 2021 | Suomenlinna |
| v4.4.0 | 15 March 2022 | Vanha Rauma |
| v4.5.0 | 2 February 2023 | Struven Ketju |
| v4.6.0 | 20 May 2024 | Sauna |
| v5.0.0 | 24 February 2025 | Tampella |

### Stop releases

When updating an installed Sailfish OS from an earlier release, for example after device factory reset, there are several stop releases which must not be skipped and have to be installed before continuing on the path to subsequent releases. These releases provide new functionality that is not compatible with previous releases and have to be traversed in order not to put the Sailfish OS installation into an unstable state.
| Software version | Release date | Name |
| v1.0.2.5 | 27 December 2013 | Maadajärvi |
| v1.1.2.16 | 25 February 2015 | Yliaavanlampi |
| v1.1.7.28 | 31 August 2015 | Björnträsket |
| v1.1.9.30 | 22 October 2015 | Eineheminlampi |
| v2.0.0.10 | 3 November 2015 | Saimaa |
| v2.0.5.6 | 22 November 2016 | Haapajoki (only a stop release for some devices, e.g., the Jolla C / Intex Aquafish) |
| v2.2.0.29 | 7 June 2018 | Mouhijoki |
| v3.0.0.8 | 11 November 2018 | Lemmenjoki |
| v3.2.0.12 | 5 November 2019 | Torronsuo |
| v3.4.0.24 | 13 October 2020 | Pallas-Yllästunturi |
| v4.0.1.48 | 16 February 2021 | Koli |
| v4.1.0.24 | 27 May 2021 | Kvarken |
| v4.2.0.21 | 16 September 2021 | Verla |
| v4.3.0.15 | 16 February 2022 | Suomenlinna |
| v4.4.0.72 | 30 September 2022 | Vanha Rauma |
| v4.5.0.25 | 29 February 2024 | Struven ketju |
| v4.6.0.15 | 20 September 2024 | Sauna (the final release for Jolla Tablet, Jolla C, Xperia X, and Gemini PDA) |

### Porting

The Sailfish website publishes an online compendium of knowledge, links and instructions on porting issues.

### Using Android software running on Sailfish OS

In addition to its native applications, Sailfish can run some Android applications by installing them from an application store or directly through an APK file. Supported Android versions are 4.1.2 "Jelly Bean" on the original Jolla phone; 4.4.4 "Kit-Kat" on the Jolla C, Jolla tablet and Xperia X; 8.1.0 "Oreo", 9 "Pie" and 10 (depending on the Sailfish OS release) on Xperia XA2, Xperia 10 and Xperia 10 II. Problems can arise if these applications were built without following Android standards about controls, which might not display correctly and so become unusable.
Sailfish OS uses Alien Dalvik, a proprietary Android compatibility layer. It does not emulate Android, but instead implements its APIs by adapting the Android Open Source Project (AOSP) code to run as an application. Android applications can thus run at native speed without any perceivable slow-down. Sailfish can run both native Sailfish and Android software simultaneously, with the user switching between them on the fly.
Starting with Alien Dalvik 8.1 (also called "Android App Support" since then), it uses LXC to improve security by better isolation, in the same way the open source Android compatibility layer Anbox is doing.

## Hardware overview
### Advantages of the Mer standard

Sailfish OS can be used on any hardware with Linux-kernel support and compatible with the middleware utilising the Mer core. Community enthusiasts have ported Sailfish OS to a number of devices this way. Instead of designation to a specific reference hardware platform, a VirtualBox implementation with the Sailfish SDK is available for development on Linux, OS X and Windows operating systems. This virtual machine implementation contains the whole Sailfish OS isolated from local resources and the local OS to enable convenient evaluation of the behaviour and performance of coded or ported software before deployment on real devices.

### Jolla devices

* Jolla Community Phone (A paid subscription is required to receive software updates. On C2 after 12 months.):
** Jolla C - Limited edition for the Sailfish OS community and developers. Announced in 2016. Not supported anymore.
** Jolla C2 - Reference device designed for the Sailfish community. Delivery starting 2024.
* Jolla Tablet - Crowdfunding project that did not deliver.
* Jolla Phone - First Sailfish phone.

### Devices from other vendors licensing Sailfish OS

Manufacturers can provide mobile equipment with a licensed Sailfish OS, or as open source, or combining both and including their own or the operator's modifications and branding for specific markets or purposes.
* Sony Xperia 10 III - via Sailfish X
* Sony Xperia 10 II – via Sailfish X
* Sony Xperia 10 Plus – via Sailfish X
* Sony Xperia 10 – via Sailfish X
* Planet Computers Gemini PDA – via Sailfish X
* Sony Xperia XA2 Plus – via Sailfish X
* Sony Xperia XA2 Ultra – via Sailfish X
* Sony Xperia XA2 – via Sailfish X
* Sony Xperia X – via Sailfish X

### Community enthusiasts' ports to devices from other vendors

Due to the relative ease of porting and the open source license, Sailfish OS has also been unofficially ported to other 3rd-party devices. The Hardware Adaptation Development Kit for porters has been published and is free. These ports are mostly published on the Maemo and XDA Developers forums, and in the Mer wiki a list of the ports is compiled. Due to license restrictions, proprietary parts or extensions such as the Alien Dalvik compatibility layer for Android apps are not included. However they can be added, e.g. when a manufacturer or distributor turns it from the community version into an officially supported version for a particular device. From the originally more than 80 ports, there are about 19 ports that are still in active development – as of March 2019 – meaning they have been updated to Sailfish 3:
* Alcatel Idol 3
* Fairphone 2
* F(x)tec Pro1
* HP TouchPad
* Motorola Moto Z Play
* Motorola Photon Q
* Motorola Moto X Force
* Motorola Moto X 2014
* Motorola Moto G 2014
* Motorola Moto G 2015
* Motorola Moto G4 Plus
* OnePlus X
* OnePlus One
* OnePlus 3
* OnePlus 3T
* OnePlus 5
* OnePlus 5T
* PinePhone
* Samsung Galaxy A5
* Siemens GigaSet GX290 – via ADB loader
* Sony Xperia X Compact
* Xiaomi Redmi 2
* Volla Phone/Volla Phone X
* Xiaomi Redmi Note 3
* Xiaomi Redmi Note 4
* Xiaomi Redmi 5 Plus
* Xiaomi Redmi 4X
To display the ease of porting Sailfish OS to other devices, Jolla showed created ports and community ports at events like the Mobile World Congress, Slush and FOSDEM:
* Nokia N950
* Nokia N9
* Google Nexus 7
* Google Nexus 4
* Samsung Galaxy S3
* Xiaomi Mi 2
* TCL Idol X950
* Google Nexus 5
* Fairphone 2
* Sony Xperia X
* Jolla Sailfish Watch
* Sony Xperia XA2
* Planet Computers Gemini PDA
* a feature phone similar to the Nokia 3310 assumed to be the Chinese Kingsun EF33

## OS development status

Sailfish OS is promoted by Jolla and supported by the open Sailfish Alliance established in 2011, a group established to unite OEM and ODM manufacturers, chipset providers, operators, application developers and retailers. On 16 August 2012, the user interface was reported to be ready for release. Jolla's CEO Jussi Hurmola stated in a ZDNet interview, " ... Our UI is ready now, we haven't released it yet, we will save it for the product launch and the platform is getting up now so the project looks pretty nice".
The next day, Jolla's CEO Marc Dillon said on social networking website Twitter that the company had reached the first development target. Sailfish was debuted by the Jolla team, including a worldwide internet stream, as a demo of the OS, and the UI and SDK during the Slush event in Helsinki, Finland, on 21–22 November 2012. The alpha stage of Sailfish OS SDK was published at the end of February 2013 and was made available for free download.
On 16 September 2013, Jolla announced that its OS had been made compatible with Android applications and hardware. The first telephone to use it was launched on 27 November 2013 at a pop-up DNA Kauppa shop in Helsinki. The first 450 telephones were sold at this event, while the rest of the preordered devices were shipped shortly after.
In August 2015, version 1.1.9 "Eineheminlampi" was released, which added the main elements of the revamped Sailfish OS 2.0 user interface.
Sailfish OS 2.0.0 was launched with the Jolla Tablet, and existing devices, both smartphones and tablets, from Jolla's official distribution channels are supported with upgrade to Sailfish OS 2.0.0 and following updates.
In May 2016 Jolla announced the Sailfish Community Device Program, supporting developers and members of Sailfish OS community.

## Aurora OS

Jolla staff met with members of the Russian technology community to break ground on the new software and promote Sailfish OS, as part of Jolla's BRICS strategy. As a result of those efforts, on 18 May 2015 the Russian minister of communications Nikolai Nikiforov announced plans to replace Apple's iOS and Google's Android platforms with new software based on Sailfish. He intends it to cover 50% of Russian needs in this area during next ten years, in comparison to the 95% currently covered with western technology. The Russian version is currently being developed under the brand name Mobile OS "Aurora" (мобильная ОС «Аврора»), before 2019 as "Sailfish Mobile OS RUS". The Chinese multinational technology company Huawei was in talks with the Russian Ministry of Communications to install Aurora OS on tablets for Russia’s population census by August 2020. Jolla has cut business ties with Russia in 2021.

## Sailfish Alliance

Sailfish Alliance is the open alliance established in 2011 by Jolla company to support the MeeGo ecosystem with new products, services and business opportunities around or using Sailfish OS, a Linux operating system combining Mer with proprietary components from Jolla and other parties, for various purposes and mobile devices.
The alliance is seen as a competitor to other groups like Android's Open Handset Alliance.
In 2011 some of the MeeGo team working at Nokia left, and were funded by Nokia though their "Bridge" program to fund spin-out projects by ex-employees. The Sailfish Alliance has sought to collaborate between the Finnish software developers, and overseas handset manufacturers, some of which are in China. The news media reports that a number of manufacturers in China and India want an alternative to Android.
The Alliance aims to "unite OEM and ODM manufacturers, chipset providers, operators, application developers and retailers."

### Business strategy

The aim of the Alliance is to offer unique differentiation opportunities and sustainable competitive advantage for OEM and ODM manufacturers, chipset providers, operators, application developers, retailers and other interested in sides.

## Sailfish Secure

Sailfish Secure is an open and secure mobile phone platform, based on Sailfish OS. It was introduced publicly in Barcelona, Spain at the Mobile World Congress on 2 March 2015 where plans for Sailfish Secure were presented.
It is based on a security-hardened version of Sailfish OS and SSH's communication encryption and key management platform. It is developed by Jolla (the Sailfish OS designer and developer) together with SSH Communications Security (the inventor of Secure Shell SSH protocol) in collaboration with the Sailfish Alliance.
Sailfish Secure is marketed as having a hardware platform independent approach that allows concept adaptation to local needs, and collaboration with other security partners. End customers like governments or large corporations are able to adapt the product to their preferred or used hardware platform, as it is not tied to a specific hardware or configuration.