# timescale.info > timescale.info runs OpenChronology. OpenChronology is a free, open-source timeline editor for exact dates at any scale, from deep time to fractions of a second, with sources on every event. It runs on the website, as a desktop app for Windows, macOS and Linux, as a single offline HTML file, and on your own server. It is free software under the GNU GPL version 3, with no payments or paid features. Times are stored exactly, as whole numbers or fractions, so dates before year 1 and fractions of a second are kept as they are. ## Start here - [Explore timelines](https://timescale.info/explore): search public timelines and their events by title and notes - [Frequently asked questions](https://timescale.info/help/faq): Short answers to common questions about OpenChronology: what it is, whether it is free, accounts, where data is kept, offline use, file formats and dates. - [Using OpenChronology](https://timescale.info/help/guide): A walk through OpenChronology: making a timeline, adding moments and durations, zooming from millennia to fractions of a second, and sharing it. - [Download](https://timescale.info/download): the desktop app, the offline file and server packages ## Who it is for - [Educators](https://timescale.info/for/educators): Free, open-source timelines for teaching. Students read without an account and propose changes you review, and every moment can carry its sources. - [Researchers](https://timescale.info/for/researchers): OpenChronology for research: exact times at any scale, sources and date precision on each moment, saved history, and export in open formats. - [Investigators](https://timescale.info/for/investigators): OpenChronology for investigations: events and causal factors charts, sources and date precision on each moment, and the saved history of every revision. - [Operations](https://timescale.info/for/operations): OpenChronology for operations: syslog and journald receivers, a log importer for syslog, Apache, nginx and JSON lines, live updates and retention. - [Writers](https://timescale.info/for/writers): OpenChronology for writers and worldbuilders: story timelines and canons, storylines on tracks of their own, your world's calendar, and co-writers. - [Developers](https://timescale.info/for/developers): OpenChronology for developers: an HTTP API described in OpenAPI 3.1, scoped API keys, sandboxed plugins, log receivers and self-hosted server packages. ## Help - [Administration, storage limits and automation](https://timescale.info/help/administration): Run an OpenChronology server: the first administrator, storage quotas, the landing page, IndexNow, page caching, terms, API keys and other operator settings. - [HTTP API](https://timescale.info/help/api): The HTTP API that the web app, the desktop app and the command-line tools use: its OpenAPI description, how to call it, and its warnings. - [Timeline and query contract](https://timescale.info/help/architecture): How OpenChronology stores and exchanges timelines: the .ochx and .och formats, exact times, window summaries, saved history and server operations. - [Accounts, sessions and deployment](https://timescale.info/help/authentication): Sign-in on an OpenChronology server: passwords, passkeys, two-factor codes, directory sign-in, human verification, and connecting the desktop app. - [Benchmarks](https://timescale.info/help/benchmarks): How OpenChronology's speed holds up as timelines grow: measured times for saves, searches, downloads and interactions on each storage backend. - [Browsing, popularity and account standing](https://timescale.info/help/browsing): How Explore lists, searches and ranks timelines and events: established accounts, standing against spam, popularity, trends and related timelines. - [Timeline size and platforms](https://timescale.info/help/capacity): How large a timeline can be: up to 200,000 moments, durations and relationships, which platform suits which size, and how the app advises you. - [Dashboard and timeline collaboration](https://timescale.info/help/collaboration): Working on timelines together: collaborators and permissions, forks and duplicates, saving while others save, pull requests, and saved history. - [Comparison of timeline tools](https://timescale.info/help/comparison-of-timeline-tools): OpenChronology beside TimelineJS, Aeon Timeline, Chronos, Time.Graphics, Preceden, Tiki-Toki and Timeline: dates, sources, size, offline use, price. - [Comparing timelines and live viewing](https://timescale.info/help/comparison): Compare timelines side by side or combined on one axis, keep a comparison as a public page, and see others' edits live. - [Building and testing](https://timescale.info/help/development): Run OpenChronology from source: the development server, package managers, the offline file and its editions, the desktop app, tests, CI and releases. - [Docker deployment](https://timescale.info/help/docker): Run your own OpenChronology server with Docker Compose: public hosting, upgrades and backups, and email for account security. - [Durations](https://timescale.info/help/durations): Durations: periods with a start and an end, anchored to times or to moments, with notes and metadata like moments, drawn as bands on the timeline. - [Timelines from files](https://timescale.info/help/file-populator): Make a timeline from the files on your computer in the desktop app: a moment for each photo, video, recording or document, at the time you choose. - [Guest and standalone editing](https://timescale.info/help/guest-editing): Editing without an account: the guest editor and the offline HTML file keep timelines in memory, and how to keep your work before closing. - [Images and copyright](https://timescale.info/help/images): Images on timelines: icons, backgrounds and a timeline's own picture are linked where they are hosted, not copied, and what the service does with them. - [Installing a server](https://timescale.info/help/install): Install your own OpenChronology server: a package for Debian, Ubuntu, Fedora, RHEL, Arch, FreeBSD, macOS or Windows, Docker Compose, Nix, or from source. - [The systemd journal to timelines](https://timescale.info/help/journald): Follow the systemd journal into timelines: each journal entry becomes a moment, live, routed to timelines by unit and fields, through the API. - [Copyright, GPLv3, and distributions](https://timescale.info/help/licensing): OpenChronology's licence, the GNU GPL version 3: where the source and releases are, contributions, and how licence changes are handled. - [Importing log files](https://timescale.info/help/log-import): Import log files into timelines: syslog, Apache, nginx, JSON lines and journald exports, one moment per entry at its exact time, with its fields kept. - [Reports and moderation](https://timescale.info/help/moderation): Reporting timelines and accounts, sensitive-content labels, and how a site's administrators review reports and restrict what breaks the rules. - [Nix and NixOS](https://timescale.info/help/nix): Install OpenChronology with Nix or NixOS: the flake's packages, nix-env without flakes, and the NixOS module that runs a server with PostgreSQL. - [Timeline plugins](https://timescale.info/help/plugins): Timeline plugins: icons, headings, backgrounds, themes, charts and fields that extend moments and durations, where they run, and how to publish them. - [Relationships](https://timescale.info/help/relationships): Relationships link two events on a timeline, drawn as arcs, and links join events across timelines: how to add, browse and remove them. - [Data retention and quick deletion](https://timescale.info/help/retention): Keep only a timeline's recent past, for logs that keep growing; stop keeping saved history; and delete everything in a view. - [Searching a timeline](https://timescale.info/help/search): Search the open timeline by its events' titles and notes: how matching and ranking work, and how the server stores and serves the search. - [Public example timelines](https://timescale.info/help/seeding): The example timelines a new server can load: how to load them, the plugins and time conventions they use, and the World War II campaign comparison. - [Sharing timelines](https://timescale.info/help/sharing): Share timelines: their addresses, links to events and views, the share dialog, link previews, what search engines get, and embedding on other sites. - [Syslog to timelines](https://timescale.info/help/syslog): Receive syslog over UDP and TCP into timelines: each message becomes a moment, routed to timelines by rules, live, through the API. - [Entity tags and separation](https://timescale.info/help/tags): Tags on events: short labels such as war or trade, how to add them, filter by them, and separate a timeline into tracks by tag. - [Shifting and scaling times](https://timescale.info/help/time-mapping): Shift or scale the times of many events at once, for good: a whole timeline or the events a separation selects, by an offset or a factor. - [Timeline time presentation](https://timescale.info/help/time-presentation): How a timeline shows its times: calendar dates, numbers, units or your own format, with exact times underneath and dates before year 1. - [Project overview](https://timescale.info/help/readme): OpenChronology is a free, open-source timeline editor for exact dates at any scale, from deep time to fractions of a second, with sources on every event. ## API - [HTTP API reference](https://timescale.info/docs/api): every operation, who may call it, and example bodies - [OpenAPI 3.1 description](https://timescale.info/api/openapi.json): the same, as JSON ## Public timelines - [Studying the past · history of historiography and historical methods](https://timescale.info/athan/historiography-history): A history of the study of history: how people preserve records, investigate evidence, explain change and debate accounts of the past. Historiography concerns… - [Studying life · history of biology, evidence and discovery](https://timescale.info/athan/biology-study-history): A history of how people study living things: observations, collections, dissections, experiments, instruments, quantitative models and molecular measurements… - [Turkish · history of sounds, writing and varieties](https://timescale.info/athan/turkish-language-history): A history of Turkish in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Greek · history of sounds, writing and varieties](https://timescale.info/athan/greek-language-history): A history of Greek in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Swedish · history of sounds, writing and varieties](https://timescale.info/athan/swedish-language-history): A history of Swedish in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Hungarian · history of sounds, writing and varieties](https://timescale.info/athan/hungarian-language-history): A history of Hungarian in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing… - [Romanian · history of sounds, writing and varieties](https://timescale.info/athan/romanian-language-history): A history of Romanian in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Czech · history of sounds, writing and varieties](https://timescale.info/athan/czech-language-history): A history of Czech in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Polish · history of sounds, writing and varieties](https://timescale.info/athan/polish-language-history): A history of Polish in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing communities… - [Ukrainian · history of sounds, writing and varieties](https://timescale.info/athan/ukrainian-language-history): A history of Ukrainian in speech and writing, following inherited sound patterns, contact, alphabets, manuscripts, print, codification and changing… ## Optional - [The help in full](https://timescale.info/llms-full.txt): every help page above, as Markdown, in one file - [Source code](https://github.com/openchronology/timeline-app): the repository, its releases and issues