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layout: default

title: Frequently Asked Questions (FAQ)

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<p>&uarr; <a href="docs.html">Documentation</a></p>

<div class="desc">

<img src="/img/faq-128x128.png" width="64" height="64" alt=""/>

<h1>Frequently Asked Questions</h1>

<p>...and their answers</p>

<p><b>Sections:</b>

<a href="#building">Building</a> &middot;

<a href="#features">Features</a> &middot;

<a href="#upgrading">Upgrading</a> &middot;

<a href="#misc">Miscellaneous</a>

<h2 id="building">▶ Building</h2>

<h3>Which operating systems are supported?</h3>

<p>Libosmium and other related software on this site is developed on Linux

and works well there. With tiny exceptions everything also works on Mac OS/X

out of the box. Most software also works on Windows. A CMake configuration

which should work on all operating systems is supplied for all projects.</p>

<h3>I can't find out how to build the Osmium Library?</h3>

<p>The C++ Osmium Library is a header-only library. You dont' have to build

it. Just install the header files and include them as needed from your code.</p>

<h3>Which build system is used?</h3>

<p>We are using <a href="https://cmake.org/">CMake</a>.</p>

<h2 id="features">▶ Features</h2>

<h3>Can Osmium work with OSM history files? Change files? Changesets?</h3>

<p>Yes. They are all supported. See the <a

href="/libosmium/manual.html">manual</a> for details.</p>

<h3>Can Osmium do Coordinate Transformations?</h3>

<p>Yes. Osmium has builtin support for the OSM native format WGS84 (EPSG 4326)

and Web Mercator (EPSG 3857). It can also use the <a

href="http://proj4.org">PROJ.4</a> library to transform to about any

coordinate reference system out there.</p>

<h2 id="upgrading">▶ Upgrading</h2>

<h3>What is the difference between "old" and "new" Osmium?</h3>

<p>The "old" Osmium was developed from 2010 to 2013. With the experience

gained and with the new possibilities of C++11 we started on the "new"

Osmium in 2013, a more or less complete rewrite of the C++ Osmium Library.

Today the "new" Osmium Library has all the functionality of the old one plus

a lot more.</p>

<p>The old Osmium is still available from <a

href="https://github.com/joto/osmium">github.com/joto/osmium</a>, but it is in

maintainance mode, ie no new functionality will be added.</p>

<p>Unless you don't have a C++11 capable compiler, we recommend using

the "new" osmium available from this web site.</p>

<h3>Where is "osmjs"?</h3>

<p>The "old" Osmium had a command line program called "osmjs" that allowed you

to use the functionality of the Osmium C++ library from Javascript. This has

been superseeded by the <a href="/node-osmium/">Node Osmium</a> NodeJS module.

The NodeJS module allows you to use thousands of existing NodeJS modules out

there in your program making this approach much more flexible.</p>

<h2 id="misc">▶ Miscellaneous</h2>

<h3>Wait, I am confused! Is Osmium a library or a program or what?</h3>

<p>The core is a <a class="ext"

href="https://en.wikipedia.org/wiki/Header-only">C++ header-only library</a>

called "<a href="/libosmium/">Osmium Library</a>" or "libosmium", but sometimes

just called "Osmium". Built on top of that are many programs with their own

names, one is the command line multipurpose "<a href="/osmium-tool/">Osmium

Tool</a>" or short "Osmium". In addition there are bindings of the C++ library

for Javascript ("<a href="/node-osmium/">Node Osmium</a>") and Python ("<a

href="/pyosmium/">PyOsmium</a>").</p>

<p>The <a class="ext" href="https://github.com/joto/osmium">old version</a> of

the Osmium Library was also just called "Osmium".</p>

<h3>I don't want to program in C++. Can I use Osmium from other languages?</h3>

<p>Yes. There is the <a href="/node-osmium/">Node Osmium</a> NodeJS module for

Javascript developers (written by Dane Springmeyer and Jochen Topf) and the

<a href="/pyosmium/">PyOsmium</a> Python module (written by Sarah Hoffmann).

Not all functionality available from C++ is available through those

modules and you'll take a performance hit, but they are much easier to use

for the average programmer.</p>

<p>If you are interested in making Osmium available in other languages, come

<a href="/contact.html">talk to us</a>.</p>