Hi Petr!
Thanks for reaching out! Sentry is open source inits roots, and we started specializing in Python, but we now support a ton of people using JavaScript along with many other programming languages. For a full list of our SDKs, see this document:
https://docs.sentry.io/clients/At the end of the day, some of our most obvious differentiators from Rollbar are our breadcrumbs and release tracking features and pricing. Our breadcrumbs can help you reproduce errors for enhanced troubleshooting and resolution, and our release tracking integrates with commit data to suggest assignees of issues. Our smallest paid plan gives you 100,000 events and unlimited users for $29/month - compared to $49/month for 100k events at Rollbar; our largest non-custom (enterprise) contract gives you 4mm events for $499 - compared to $599 for 4mm events at Rollbar. All of our plans are discounted by 10% for an annual contract.
Would you be willing to share more about your use-case and objectives (i.e what platform you use)? If so, I would probably more explicitly differentiate Sentry from Rollbar.
Ultimately, I'd encourage you to opt into our Free 14-day trial and compare Rollbar from Sentry side-by-side! We'd love to hear your thoughts regardless.
Let me know what you think!