LineageOS

CyanogenMod (often abbreviated "CM") was a popular[13] open-source operating system for smartphones and tablet computers, based on the Android mobile platform. Although only a subset of total CyanogenMod users elected to report their use of the firmware,[14] as of 23 March 2015, some reports indicated over 50 million people running CyanogenMod on their phones.[13][15] It was also frequently used as a starting point by developers of other ROMs.

In 2013, the founder, Stefanie Kondik, obtained venture funding under the name Cyanogen Inc. to allow commercialization of the project.[16][17] In her view, the company did not capitalize on the project's success and in 2016 she either left or was forced out[18][19] as part of a corporate restructure which involved a change of CEO, closure of offices and projects, and cessation of services.[20] The code itself, being both open source and popular, was quickly forked under the new name LineageOS and efforts began to resume development as a community project.

CyanogenMod offered a number of features and options not available in the official firmware distributed by most mobile device vendors. Features supported by CyanogenMod included native theme support,[21] FLAC audio codec support, a large Access Point Name list, Privacy Guard (per-application permission management application), support for tethering over common interfaces, CPU overclocking and other performance enhancements, root access, soft buttons and other "tablet tweaks," toggles in the notification pull-down (such as Wi-Fi, Bluetooth and satellite navigation), and other interface enhancements. Many of the features from CyanogenMod were later integrated into the official Android code base. CyanogenMod's developers said that it did not contain spyware or bloatware.[22][23] CyanogenMod was also said to perform better and be more reliable than official firmware releases.[24]

Like CyanogenMod, the LineageOS project is developed by many device-specific maintainers and uses Gerrit for its code review process. It also retained the old versioning format (for example, Android 7.1 is LineageOS 14.1).

Prior to the official launch of LineageOS, many developers from XDA had already developed unofficial versions of LineageOS from the source code.

• On 22 January 2017, the first 14.1 and 13.0 official builds started to be made available, following the official announcement in a blog post.[25]
• On 11 February 2018, the 13.0 builds were stopped,[26] while the source code remains available and security fixes are still accepted on Gerrit.
• On 26 February 2018, the first 15.1 official builds started to be available on certain devices, following official announcement in a blog post.[27] The 14.1 versions of Lineage OS were to remain in active development, but without feature advancements.
• On 24 February 2019, the 14.1 builds were stopped and 15.1 builds moved to a weekly cadence[28]
• On 1 March 2019, the first 16.0 official builds started to be available, following official announcement.[29] The 15.1 branch remains in active development, but without feature advancements.
• On 28 February 2020, the 15.1 builds were stopped in preparation for the 17.1 release.[30]
• On 1 April 2020, the first 17.1 builds started to be available, following official announcement.[31] The 16.0 builds are moved to a weekly cadence while the branch remains in active development, but without feature advancements.

All the released builds are signed with LineageOS' private keys.[25]

Builds were released on a weekly basis until 12 November 2018, when the release cycle for devices has changed: the latest LineageOS branch is built daily, with devices receiving a "nightly" OTA update, while devices on the older branch were moved to a weekly release cycle.[32]

LineageOS allows the community to get involved with the development in various ways. Gerrit is used for the code review process of both the operating system and the infrastructure.

The wiki, containing information regarding installation, support, and development of LineageOS, is also open to contributions through Gerrit. Other Lineage platforms include Crowdin for managing translations, Gitlab Issues for bug tracking, and a stats page, which displays the number of active installations from users which opt-in to report this statistic. There is also an official subreddit, r/lineageos, and two IRC channels hosted on Freenode (#lineageos and #lineageos-dev).

The XDA Developers forums have been used by members of the Lineage community since the first inception of the software, many devices are left unsupported by official releases so community members develop their own Unofficial-ROMs that allow older phones to use Lineage. These unofficial releases are often bundled with software intended to aid the user's experience that would otherwise be unseen in an official release. They also come with known bugs and security issues that may not be seen in official releases.

During August 2017 the LineageOS team held a Summer Survey[33] in which they asked users for feedback to improve the development of the operating system. The results were published[34] in October and, according to the team, they used the gathered data to improve the upcoming LineageOS 15 release. The second Summer Survey was conducted in August 2018.[35]

As a response to one of the main suggestions received during their first public survey, LineageOS launched a section on their blog titled "LineageOS Engineering Blog" where Lineage maintainers and developers can contribute articles discussing advanced technical information pertaining to Android development.[36]

LineageOS is also known for posting a "regularly irregular review"[37] on its blog in which the active development of the work is discussed.

LineageOS includes many essential and useful apps, but like its predecessor, CyanogenMod, it is free from unnecessary software often pre-installed by a phone's manufacturer or carrier that is considered to be bloatware.[43][22]

Current

• AudioFX – Audio optimizer with presets to alter the listening experience.
• Browser – A lightweight browser that relies on the System Webview, for low-end devices, also known as Jelly.
• Calculator – which resembles a four-function calculator and offers some more advanced functions.
• Calendar – Calendar functionality with Day, Week, Month, Year or Agenda views.
• Camera – Dependent on device specification will take video or photos, including panoramic. It can also be used to read QR codes. This app is also known as Snap.
• Clock – World clock, countdown timer, stopwatch and alarms.
• Contacts – Phonebook for numbers and email addresses.
• cLock - A weather widget.
• Terminal - A simple and standard terminal app.
• Email – Email client that handles POP3, IMAP and Exchange.
• Files – A simple file manager to move, copy and rename files on internal storage or SD card.
• FlipFlap – An app for smart flip covers, only included on select devices.
• FM Radio - An app for listening to FM radio broadcasts, included on devices with an FM tuner.
• Gallery – Organize photos and videos into a timeline or albums for easy viewing.
• Messaging –An MMS/SMS messaging app.
• Music – A simple music player, also known as Eleven.
• Phone – for making calls: includes speed dial, phone number lookups and call blocking.
• Recorder – A screen and/or sound recorder.
• Trebuchet – A customizable launcher.

Former

• Gello - A browser based on Chromium and developed by CyanogenMod. This app is now replaced by Jelly.
• Yahoo Weather Provider - A weather provider
• WeatherUnderground Weather Provider - A weather provider
• Themes - Originally an app by itself, now integrated into the settings app.

Although they are not included in LineageOS as such due to legal issues,[44] users can flash the normal Google apps, including the Google Play Store and Play Apps, with a Zip package, usually referred to as gapps, while installing LineageOS.

LineageOS offers several features that Android Open Source Project (AOSP) does not include. Some of these features are:

As LineageOS evolved through development, the Trust interface was introduced for all the LineageOS 15.1 builds released since 12 June 2018.[48] The interface can be found on supported devices under Security and Privacy tab under the Settings option, and enables the user to "get an overview of the status of core security features and explanations on how to act to make sure the device is secure and the data is private".

Additionally, while carrying out any action on the device, the trust icon is displayed, notifying the user that the action is safe.

The number of devices supported by LineageOS has increased over time, with 127 for v16 and v17.1 as of May 1, 2020.[10][49] Official builds on currently supported development branches are labeled as either "nightly", "weekly", or "monthly". For the first two months of the project, parallel experimental builds were also produced, allowing in-place upgrades from previous CyanogenMod installations and easing migration to LineageOS.[49][50][51][52]

Replicant is a completely free software variant of LineageOS, with all kernel blobs and non-free drivers removed.

As a response to the refusal for several reasons of support for signature spoofing in official builds,[56] a LineageOS fork with microG[57] services included, known as "LineageOS for microG", was created. The project ships custom builds of LineageOS with the required patch and native F-Droid support, bundled with the MicroG project's free re-implementation of proprietary Gapps.[58][59] In other respects it follows upstream, shipping OTA updates every seven days.[60]

/e/ is a fork of LineageOS created by Gaël Duval that is intended to be "free from Google". It replaces Google Play Services with MicroG, a free and open-source implementation of Google APIs.[61]

• Official website