matrix-spec/supporting-docs/_posts/2015-08-19-faq.md

---
layout: post
title: FAQ
date: 2015-08-19 16:58:07
categories: guides
---
<link href="/docs/guides/css/faq.css" type="text/css" rel="stylesheet" />

# FAQ
{:.no_toc}

Categories
----------
{:.no_toc}

[General](#general)

[Quick Start](#quick-start)

[Standard](#standard)

[APIs](#apis)

[Reference Implementations](#reference-implementations)

|

FAQ Content
-----------
{:.no_toc}


* TOC
{:toc}

### General

##### What is Matrix?

Matrix is an ambitious new open standard for open, distributed,
real-time communication over IP. It defines interoperable Instant
Messaging and VoIP, providing pragmatic HTTP APIs and open source
reference implementations for creating and running your own real-time
communication infrastructure.

##### What is Matrix's Mission?

Matrix.org's initial inspiration and goal has been to fix the problem of
fragmented IP communications. But Matrix's real potential and ultimate
mission is to be a generic messaging and data synchronisation system for
the web - allowing people, services and devices to easily communicate
with each other with full history.

##### What does Matrix provide?

Today Matrix provides a new [open standard](/docs/spec),
[APIs](/docs/api) to integrate a service to the Matrix ecosystem and
reference [open source
implementations](http://github.com/matrix-org/synapse) of the standard.

##### What does this mean for users?

The aim is to provide an analogous ecosystem to email - one where you
can communicate with pretty much anyone, without caring what app or
server they are using, using whichever app & server you chose to use,
and a nice neutral identity system like an e-mail address or phone
number to discover people to talk to.

##### What kind of company is Matrix.org?

Matrix is an open initiative which acts as a neutral custodian of the
Matrix standard. It's not actually incorporated anywhere at the moment
but we are looking at the best legal structure for the future. We are
committed to keeping the Matrix project open.

##### Who is funding Matrix.org?

We have been given permission by our employers, Amdocs, to work on
Matrix as an independent non-profit initiative.

##### Who is building Matrix?

We're a team of ~10 people with decades of experience building custom
VoIP and Messaging apps for mobile network operators. Most of us have
day jobs at Amdocs or OpenMarket, but we are supported by a mix of
freelancers and volunteers.

##### Why are you called Matrix?

We are called Matrix because we provide a structure in which all
communication can be matrixed together.

##### Why have you released this as open source?

We believe that any open standard defining interoperable communication
needs to be justified, demonstrated and validated with transparent open
source implementations. For Matrix to achieve its mission of making all
communications services interoperable we believe it needs to be truly
open, giving people access to take all the code we produce and to use
and build on top of it.

##### What do you mean by open?

Matrix is an open standard, meaning that we have freely published the
details for how to interface with Matrix compliant servers and clients,
and encourage anyone and everyone to interface with them.  We also
ensure the standard is not encumbered by any known patent licensing
requirements.

| 

Matrix is also open source, meaning that we have released the source
code of the reference servers and clients to the public domain under the
[Apache Licence v2](http://www.apache.org/licenses/LICENSE-2.0.html), to
encourage anyone and everyone to run their own servers and clients, and
enhance them and contribute their enhancements as they see fit.

##### What does federated mean?

Federation allows separate deployments of a communication service to
communicate with each other - for instance a mail server run by Google
federates with a mail server run by Microsoft when you send email from
@gmail.com to @outlook.com.

|

Federation is different to interoperability, as interoperable clients
may simply be running on the same deployment - whereas in federation the
deployments themselves are exchanging data in a compatible manner.

|

Matrix provides open federation - meaning that anyone on the internet
can join into the Matrix ecosystem by deploying their own server.

##### How is this like e-mail?

When email was first set up in the early ‘80s, companies like Compuserve
and AT&T and Sprint set up isolated email communities which only allowed
you to exchange mail with users on the same system.  If you got your
email from one service and your friend from another, then you couldn't
message each other.  This is basically the situation we're in today with
VoIP and IM.

##### Why has no-one done this before?

There have been several attempts before including SIP, XMPP and RCS.
 All of these have had some level of success, but
technological/usability/economic factors have ended up limiting their
success in providing true open federation.

##### What is the difference between Matrix and IRC?

We love IRC.  In fact, as of today the core Matrix team still uses it as
our primary communication tool. Between us we've written IRCds, IRC bots
and admined dreamforge, UnrealIRCd, epona, ircservices and several
others.  That said, it has some limitations that Matrix seeks to improve
on:

-   Text only
-   No history
-   No multiple-device support
-   No presence support
-   Fragmented identity model
-   No open federation
-   No standard APIs, just an archaic TCP line protocol
-   Non-standardised federation protocol
-   No built-in end-to-end encryption
-   Disruptive net-splits
-   Non-extensible

##### What is the difference between Matrix and XMPP?

The Matrix team used XMPP (Openfire, ejabberd, spectrum, asmack,
XMPPFramework) for IM before starting to experiment with open HTTP APIs
as an alternative.   The main issues with XMPP that drove us in this
direction were:

-   Not particularly web-friendly - you can't easily speak XMPP from a
    web browser. (N.B. Nowadays you have options like XMPP-FTW and
    Stanza.io that help loads with letting browsers talk XMPP).
-   Single logical server per MUC is a single point of control and
    availability. (MUCs can be distributed over multiple physical
    servers, but they still sit behind a single logical JID and domain.
    FMUC improves this with a similar approach to Matrix, but at time of
    writing there are no open implementations.)
-   History synchronisation is very much a second class citizen feature
-   Stanzas aren't framed or reliably delivered without extensions. (See
    [wiki.xmpp.org](http://wiki.xmpp.org/web/Myths#Myth_Four:_XMPP_is_unreliable_without_a_bunch_of_extensions.)
    for an XMPP take on this)
-   Multiple device support is limited. (Apparently Carbons and MAM help
    with this)
-   Baseline feature set is so minimal that fragmentation of features
    between clients and servers is common
-   No strong identity system (i.e. no standard E2E PKI, unless you
    count X.509 certs, which [are
    questionable](http://www.thoughtcrime.org/blog/ssl-and-the-future-of-authenticity/))
-   Not particularly well designed for mobile use cases: push;
    bandwidth-efficient transports. (Since the time of writing a [Push
    XEP has appeared](http://xmpp.org/extensions/xep-0357.html), and
    [wiki.xmpp.org](http://wiki.xmpp.org/web/Myths#Myth_Three:_It.27s_too_bandwidth-inefficient_for_mobile.)
    claims that XMPP runs fine over a 9600bps + 30s latency link.)

The whole subject of XMPP vs Matrix seems to bring out the worst in
people. We think of the standards as being quite different; at its core
Matrix can be thought of as an eventually consistent global JSON db with
an HTTP API and pubsub semantics - whilst XMPP can be thought of as a
message passing protocol. You can use them both to build chat systems;
you can use them both to build pubsub systems; each comes with different
tradeoffs. Matrix has a 'kitchen sink' baseline of functionality; XMPP
has a deliberately minimal baseline set of functionality. If XMPP does
what you need it to do, then we're genuinely happy for you :) Meanwhile,
rather than competing, an XMPP Bridge like [Skaverat's xmpptrix
beta](https://github.com/SkaveRat/xmpptrix) has potential to let both
environments coexist and make the most of each other's benefits.

##### What is the difference between Matrix and PSYC?

PSYC is a open federated messaging protocol loosely inspired by IRC.  In
version 1 it was a standalone protocol, and in version 2 it is being
reutilised as the messaging layer on top of GNUnet.  We honestly don't
know that much about it, beyond trying to use psycd as an XMPP\<-\>IRC
bridge in 2010. Matrix differentiates primarily by providing simple HTTP
APIs rather than the more exotic compact line protocol in PSYC v1 or the
complicated GNUnet stack in v2.  Meanwhile, Matrix doesn't provide of
the metadata protection guarantees that GNUnet/PSYC aims for.

| 

See [http://about.psyc.eu/Matrix](http://about.psyc.eu/Matrix) for
PSYC's views on Matrix.

##### What is the difference between Matrix and Tox?

Tox.im looks to be a very cool clone of Skype - a fully decentralised
peer-to-peer network.  Matrix is deliberately not peer-to-peer; instead
each user has a well-defined homeserver which stores his data and that
he can depend upon.  Matrix provides HTTP APIs; Tox.im provides C APIs.
 We haven't actually played with Tox at all yet.

##### How does Matrix compare with something like Trillian or Pidgin?

Trillian and Pidgin and similar aggregating IM clients merge all your IM
activity into a single user experience.  However, your history and
identity is still fragmented across the networks.  People can't find you
easily, and your history is fragmented (other than on the device
where the client runs).   And rather than being able to chose the right
app for the job when communicating with people, you are pushed towards
relying on a specific aggregation app.

##### What Matrix compliant apps are there?

None yet, other than our examples.  It's early days :)

##### Why do you think existing apps will ever join this?

We firmly believe it is what is right for the consumer. As people begin
to use interoperable communications tools service providers will see the
benefit and compete on quality of service, security and features rather
than relying on locking people into their walled garden. We believe as
soon as users see the availability and benefits of interoperable
services they will demand it.

##### Why aren't you doing this through the IETF? or W3C? or 3GPP?

We do recognise the advantages of working with existing standards
bodies. We have been focused on writing code and getting it out. As
Matrix matures it may well be appropriate to work with an official
standard body.

|

### Quick Start

##### How do I get an account and get started?

The quickest way is to just jump to the demo webclient at
[http://matrix.org/beta](http://matrix.org/beta) and sign up.  Please note that you can point the
webclient to access any homeserver - you don't have to use matrix.org,
although as of day 1, matrix.org is the only communal homeserver
available.

##### What can I actually do with this?

The demo webclient provides a simple chatroom interface to Matrix -
letting the user interact with users and rooms anywhere within the
Matrix federation.  Text and image messages are supported, and basic
voice-only VoIP calling via WebRTC is supported in one-to-one rooms.

##### How do I connect my homeserver to the public Matrix network?

See
[http://github.com/matrix-org/synapse](http://github.com/matrix-org/synapse)
for details

##### How do I Matrix-enable my existing app?

See the [Client-Server API
HOWTO](http://matrix.org/docs/howtos/client-server.html) for an example
of how to use Matrix's client-server API to let your app communicate
with users via Matrix.  We're currently working out the best way to
integrate your application's existing identity system with Matrix.

##### How can I write a client on Matrix?

See the [Client-Server API
HOWTO](http://matrix.org/docs/howtos/client-server.html) and the [API
docs](/docs/api) and [the Spec](/docs/spec) for all the details you need
to write a client.

##### *How can I help out with this?*

Install synapse and tell us how you get on. Critique the spec.  Write
clients.  Just come say hi on [\#matrix:matrix.org](/alpha) or the
[mailing lists](/mailman/listinfo/matrix-users)!

##### Where can I get support?

[\#matrix:matrix.org](/alpha), \#matrix on irc.freenode.net or
the [mailing lists](/mailman/listinfo/matrix-users) are your best bets.

##### How do I register custom matrix event types?

We're not yet managing a registry of custom matrix event types.  If you
have any particularly good ones you want to tell the world about, please
use the [mailing list](/mailman/listinfo/matrix-users) for now.

##### How mature is this?

We started working on Matrix in July 2014, and have opened it to the
public in September 2014.  It's early days, and under no circumstances
should you use Matrix or Synapse for anything other than experimentation
and learning at this point.  Obviously the spec and apps are maturing
rapidly, but as of the time of writing APIs are not frozen and the apps
are very much a work in progress.

|

*Sorry, the FAQ is still work in progress, the rest of it will up
soon!* *In the mean time, don't hesitate to get in touch on
[\#matrix:matrix.org](/alpha) or the [mailing
lists](/mailman/listinfo/matrix-users)!*

|

### Standard

##### What is a home server?

##### What is an identity sever?

##### Where do my conversations get stored?

##### What is a 3PID?

##### How do you do VoIP calls on Matrix?

##### Can I log into other homeservers with my username and password?

##### Why Apache Licence?

##### Can I write a Matrix homeserver?

##### How secure is this?

##### Why aren't you using an ORM layer like SqlAlchemy?  

|

### APIs

##### How do I join the global Matrix federation?

##### What ports do I have to open up to join the global Matrix federation?

|

### Reference Implementations

##### What is Matrix built on - and why?

##### How do I run my own home server?

##### Can I run my own identity server?

Yes - the reference implementation is
[sydent](https://github.com/matrix-org/sydent) and you can run your own
ID server cluster that tracks 3rd party to Matrix ID mappings. If you
want your server to participate in the global replicated Matrix ID
service then please get in touch with us. Meanwhile, we are looking at
ways of decentralising the 'official' Matrix identity service so that
identity servers are 100% decentralised and can openly federate with
each other. **N.B. that you can use Matrix without ever using the
identity service - it exists only to map 3rd party IDs (e.g. email
addresses) to matrix IDs to aid user discovery**.

##### What is Synapse?

##### Why is Synapse in Python/Twisted?

##### What are Synapse's platform requirements?

##### What are the Synapse webclient's requirements?

##### Where is the mobile app?

##### What decides the room member order on the webclient?

|

Any other question? Please contact us on
[\#matrix:matrix.org](/alpha) or the [mailing
lists](/mailman/listinfo/matrix-users)!