---
title: About Calico
canonical_url: https://docs.projectcalico.org/v3.3/introduction/
---

{{site.prodname}} provides secure network connectivity for 
containers and virtual machine workloads.

{{site.prodname}} creates and manages a flat layer 3 network, 
assigning each workload a fully routable IP address. 
Workloads can communicate without IP encapsulation 
or network address translation for bare metal 
performance, easier troubleshooting, and better 
interoperability. In environments that require an 
overlay, {{site.prodname}} uses IP-in-IP tunneling or can work 
with other overlay networking such as flannel.

{{site.prodname}} also provides dynamic enforcement of network 
security rules. Using {{site.prodname}}'s simple policy language, 
you can achieve fine-grained control over communications 
between containers, virtual machine workloads, and 
bare metal host endpoints.

Proven in production at scale, {{site.prodname}} v3.0 features 
integrations with Kubernetes and OpenShift.

> **Note**: For integrations with the OpenStack, 
> Mesos, DC/OS, and Docker orchestrators, use
> [Calico v2.6](/v2.6/introduction/). We plan 
> to resume support for these orchestrators in a future 
> v3.x release.
{: .alert .alert-info}

<a href="/{{page.version}}/getting-started/" class="btn btn-primary btn-lg">Get started</a>