index.html

---
layout: layout
preload:
  # Preload hover image
  - href: /images/lucy/lucyhappy.svg
    as: image
---

{% capture header_content %}
<div>
  <b>Gleam</b> is a <b>friendly</b> language for building
  <b>type-safe</b> systems that <b>scale</b>!
</div>
<a class="button" href="https://tour.gleam.run/">Try Gleam</a>
{% endcapture %} {% include page-header.html image="/images/lucy/lucy.svg"
alt="Lucy the star, Gleam's mascot" content=header_content %}

<main role="main">
  <section class="content home-pair intro">
    <div>
      <p>
        The power of a type system, the expressiveness of functional
        programming, and the reliability of the highly concurrent, fault
        tolerant Erlang runtime, with a familiar and modern syntax.
      </p>
    </div>
    <pre><code><span class="code-keyword">import</span> <span class="code-module">gleam/io</span>

<span class="code-keyword">pub fn</span> <span class="code-fn">main</span>() {
  <span class="code-module">io.</span><span class="code-fn">println</span>(<span class="code-string">"hello, friend!"</span>)
}</code></pre>
  </section>

  <section class="home-top-sponsors">
    <div class="content">
      <h2>Kindly supported by</h2>
      <ul>
        <li>
          <a
            class="sponsor-level1"
            href="https://lambdaclass.com/"
            rel="noopener"
            target="_blank"
          >
            <img
              src="/images/sponsors/lambda-class-black.png"
              alt="Lambda Class"
            />
          </a>
        </li>
      </ul>
      <a
        class="sponsor-level0"
        href="https://github.com/sponsors/lpil"
        rel="noopener"
        target="_blank"
      >
        and sponsors like you!
      </a>
    </div>
  </section>

  <section class="content home-pair">
    <div>
      <h2>Reliable and scalable</h2>
      <p>
        Running on the battle-tested Erlang virtual machine that powers
        planet-scale systems such as WhatsApp and Ericsson, Gleam is ready for
        workloads of any size.
      </p>
      <p>
        Thanks to a multi-core actor based concurrency system that can run
        millions of concurrent tasks, fast immutable data structures, and a
        concurrent garbage collector that never stops the world, your service
        can scale and stay lightning fast with ease.
      </p>
    </div>
    <pre><code><span class="code-keyword">fn</span> <span class="code-fn">spawn_task</span>(i) {
  <span class="code-module">task.</span><span class="code-fn">async</span>(<span class="code-keyword">fn</span>() {
    <span class="code-keyword">let</span> n = <span class="code-module">int.</span><span class="code-fn">to_string</span>(i)
    <span class="code-module">io.</span><span class="code-fn">println</span>(<span class="code-string">"Hello from "</span> <span class="code-operator">&lt;&gt;</span> n)
  })
}

<span class="code-keyword">pub fn</span> <span class="code-fn">main</span>() {
  <span class="code-comment">// Run loads of threads, no problem</span>
  <span class="code-module">list.</span><span class="code-fn">range</span>(<span class="code-number">0</span>, <span class="code-number">200_000</span>)
  <span class="code-operator">|></span> <span class="code-module">list.</span><span class="code-fn">map</span>(<span class="code-fn">spawn_task</span>)
  <span class="code-operator">|></span> <span class="code-module">list.</span><span class="code-fn">each</span>(<span class="code-module">task.</span><span class="code-fn">await_forever</span>)
}
</code></pre>
  </section>

  <section class="content home-pair">
    <div>
      <h2>Ready when you are</h2>
      <p>
        Gleam comes with compiler, build tool, formatter, editor integrations,
        and package manager all built in, so creating a Gleam project is just
        running <code>gleam new</code>.
      </p>
      <p>
        As part of the wider BEAM ecosystem, Gleam programs can use thousands of
        published packages, whether they are written in Gleam, Erlang, or
        Elixir.
      </p>
    </div>
    <pre><code><span class="code-prompt">➜ (main)</span> gleam add gleam_json
<span class="code-operator">  Resolving</span> versions
<span class="code-operator">Downloading</span> packages
<span class="code-operator"> Downloaded</span> 2 packages in 0.01s
<span class="code-operator">      Added</span> gleam_json v0.5.0
<span class="code-prompt">➜ (main)</span> gleam test
<span class="code-operator"> Compiling</span> thoas
<span class="code-operator"> Compiling</span> gleam_json
<span class="code-operator"> Compiling</span> app
<span class="code-operator">  Compiled</span> in 1.67s
<span class="code-operator">   Running</span> app_test.main
<span class="code-success">.
1 tests, 0 failures</span>
</code></pre>
  </section>

  <section class="content home-pair">
    <div>
      <h2>Here to help</h2>
      <p>
        No null values, no exceptions, clear error messages, and a practical
        type system. Whether you're writing new code or maintaining old code,
        Gleam is designed to make your job as fun and stress-free as possible.
      </p>
    </div>
    <pre><code><span class="code-error">error:</span> Unknown record field

  ┌─ ./src/app.gleam:8:16
  │
8 │ user.alias
  │ <span class="code-error">    ^^^^^^ Did you mean `name`?</span>

The value being accessed has this type:
    User

It has these fields:
    .name
</code></pre>
  </section>

  <section class="content home-pair">
    <div>
      <h2>Multilingual</h2>
      <p>
        Gleam makes it easy to use code written in other BEAM languages such as
        Erlang and Elixir, so there's a rich ecosystem of thousands of open
        source libraries for Gleam users to make use of.
      </p>
      <p>
        Gleam can additionally compile to JavaScript, enabling you to use your
        code in the browser, or anywhere else JavaScript can run. It also
        generates TypeScript definitions, so you can interact with your Gleam
        code confidently, even from the outside.
      </p>
    </div>
    <pre><code>
      

<span class="code-keyword">@external</span>(erlang, <span class="code-string">"Elixir.HPAX", "new"</span>)
<span class="code-keyword">pub fn</span> <span class="code-fn">new</span>(size: <span class="code-type">Int</span>) -> <span class="code-type">Table</span>
  


<span class="code-keyword">pub fn</span> <span class="code-fn">register_event_handler</span>() {
  <span class="code-keyword">let</span> el = <span class="code-module">document.</span><span class="code-fn">query_selector</span>(<span class="code-string">"a"</span>)
  <span class="code-module">element.</span><span class="code-fn">add_event_listener</span>(el, <span class="code-keyword">fn</span>() {
    <span class="code-module">io.</span><span class="code-fn">println</span>(<span class="code-string">"Clicked!"</span>)
  })
}</code></pre>
  </section>

  <section class="home-friendly">
    <!-- TODO: add triangles here -->
    <div class="content">
      <h2>Friendly 💜</h2>
      <p>
        As a community, we want to be friendly too. People from around the
        world, of all backgrounds, genders, and experience levels are welcome
        and respected equally. See our community code of conduct for more.
      </p>
      <p>
        <!-- Hello! If you make a PR changing this I will ban you. -->
        Black lives matter. Trans rights are human rights. No nazi bullsh*t.
      </p>
    </div>
    <!-- TODO: add Lucy here -->
    <img
      class="home-waves"
      src="/images/waves.svg"
      alt="a soft wavey boundary between two sections of the website"
    />
  </section>

  <section class="home-sponsors">
    <div class="content">
      <h2>Lovely people</h2>
      <p>
        If you enjoy Gleam consider
        <a href="https://github.com/sponsors/lpil">becoming a sponsor</a>
        (or tell your boss to)
      </p>
    </div>
    <div class="home-sponsors-list">
      <ul data-randomise-order>
        {% assign sponsors_count = site.data.sponsors | size %} {% assign
        sponsors = site.data.sponsors | sample: sponsors_count %} {% for sponsor
        in sponsors %}
        <li>
          <a href="{{ sponsor.url }}" rel="noopener" target="_blank">
            <img
              loading="lazy"
              src="{{ sponsor.avatar }}"
              class="{% unless sponsor.square_avatar %}round{% endunless %}"
              alt="{{ sponsor.name }}"
            />
          </a>
          {% endfor %}
        </li>
      </ul>
      <a data-expand-sponsors></a>
    </div>
  </section>

  <section class="home-still-here">
    <div class="content">
      <h2>You're still here?</h2>
      <p class="go-read">
        Well, that&apos;s all this page has to say. Maybe you should go read the
        language tour!
      </p>
      <a class="button" href="https://tour.gleam.run/">Let's go!</a>

      <hr />

      <h3>Wanna keep in touch?</h3>
      <p>Subscribe to the Gleam newsletter</p>
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      <p>
        We send emails at most a few times a year, and we'll never share your
        email with anyone else.
      </p>
      <p class="recaptcha-blerb">
        This site is protected by reCAPTCHA and the Google
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    </div>
  </section>
</main>