If you're interested in using GitLab, we recommend you download and install GitLab Enterprise Edition, even if you're not sure whether you will ever subscribe for a license for GitLab Enterprise Edition. You will still be able to make use of all features of GitLab Community Edition without a need for a license or registering.
GitLab is built on an open core model. That means there are two versions of GitLab: Community Edition and Enterprise Edition.
GitLab Community Edition is open source, with an MIT Expat license. GitLab Enterprise Edition is built on top of Community Edition: it uses the same core, but adds additional features and functionality on top of that. This is under a proprietary license.
Why use Enterprise Edition
To be able to use GitLab Enterprise Edition features, you need a subscription which will give you a license. If you're using Enterprise Edition without a license, you are only using functions that are MIT licensed.
This means that if you have installed GitLab Enterprise Edition without a license, you will not notice a difference with a typical Community Edition instance, but you have additional advantages:
If at any point in time you'd like to trial Enterprise Edition features, you can do this without the need of setting up a new instance or upgrading your existing instance. You simply enable the trial from within GitLab. If you're not satisfied with the Enterprise Edition features, your instance will automatically revert back to only Community Edition features after the trial has expired.
To upgrade from Community Edition to Enterprise Edition you will have to make sure you're on the same version and follow specific steps, which often require downtime. Using Enterprise Edition, changing between only Community Edition features and the full suite of Enterprise Edition features is a matter of a single click.
Why use Community Edition
If you only want to download open source software Community Edition is the best choice. This distribution does not contain proprietary code. Functionally it will behave the same as Enterprise Edition without a license.
Note that in the future if you decide to move to Enterprise Edition, an upgrade is required and may require downtime.