About Active Collab

Manage projects, track time, and bill your clients with one easy‑to‑use collaboration tool.

Our Story

We are A51, the company behind Active Collab. We're privately owned, 30 people strong, and have 8 years of experience in project management software. As simple as that.

Active Collab began as a successful open-source project, which later grew to be a very successful commercial product. All we care about is developing exceptional software and making Active Collab the best project management tool in the world.

Help & Support

At your service! Check out our help guides or get support via email every workday (8AM - 11PM CET)

General inquiries



A51 d.o.o., Novosadskog sajma 4A/30
21000 Novi Sad, Serbia


101 West Main St, Suite 101
23510 Norfolk, Virginia, USA

Send us a message

Thank you for getting in touch!We try to respond as soon as possible, so one of our Customer Service colleagues will get back to you within a few hours.Have a great day ahead!

Something went wrong. If you can't submit the form after a few retries, please send an email to contact@activecollab.com