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GNAT Pro vs Solace PubSub+

GNAT Pro logo

GNAT Pro

Developer Tools

Software development environments and toolchains for Ada, C/C++ and Rust

From
On request
Free plan
No
Visit GNAT ProFull review
Solace PubSub+ logo

Solace PubSub+

Databases

Multi-protocol event broker sold as software, cloud service or a hardware appliance

From
Free
Free plan
Yes
Visit Solace PubSub+Full review

The short version

  • Solace PubSub+ is free; GNAT Pro prices on request.
  • Where GNAT Pro falls short: no pricing published on website; requires contacting AdaCore directly for quotes.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which GNAT Pro and Solace PubSub+ actually diverge.

Attributes where GNAT Pro and Solace PubSub+ differ
AttributeGNAT ProSolace PubSub+
Starting priceOn requestFree
Free tierNoYes
PlatformsWebLinux, Self-hosted, Web, Hardware appliance
CategoryDeveloper ToolsDatabases

Identical on both: pricing model (Quote).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in GNAT Pro

Nothing recorded that Solace PubSub+ does not also cover.

Only in Solace PubSub+

  • Multi-protocol broker
  • Dynamic message routing
  • Hardware appliance
  • Event Portal
  • Guaranteed delivery
  • Mission Control
  • Topic hierarchies and wildcards
  • Kafka and MQ bridging

What people use each for

The jobs each tool is most often brought in to do.

GNAT Pro

  • Building certified avionics software meeting DO-178B/C standardsnot Solace PubSub+
  • Developing automotive embedded systems with ISO-26262 compliancenot Solace PubSub+
  • Integrating Ada, C/C++, and Rust components in single codebasenot Solace PubSub+
  • Managing software supply chain vulnerabilities and SBOMsnot Solace PubSub+
  • Supporting long-lived software systems spanning decadesnot Solace PubSub+

Solace PubSub+

  • A bank building an event mesh across regions where a Java JMS application and an MQTT mobile client must share the same topic spacenot GNAT Pro
  • An exchange or trading platform with a latency budget that needs the hardware appliance rather than a software brokernot GNAT Pro
  • An airline distributing operational events to ground systems, aircraft and partner APIs over different protocolsnot GNAT Pro
  • A manufacturer bridging factory MQTT telemetry into an enterprise Kafka estate without writing translation servicesnot GNAT Pro

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

GNAT Pro

  • No pricing published on website; requires contacting AdaCore directly for quotes
  • Vendor indicates per-user, per-year subscription model but does not disclose specific costs

Solace PubSub+

  • No pricing is published at any tier, so evaluation requires a sales engagement before you can even judge whether it is in budget, and broker tier sizing determines cost in ways buyers frequently get wrong
  • The free Standard edition has hard capacity and support limits, which makes it useful for development but means any real deployment triggers a commercial negotiation
  • The proprietary SMF protocol gives the best performance and feature coverage, so teams that lean on it acquire real switching costs even though open protocols are supported
  • Operating a self-managed high availability broker pair with disaster recovery is a specialist task, and Solace expertise is scarce in the hiring market compared with Kafka skills
  • Event Portal and Mission Control are licensed as part of platform packages, so the governance tooling that makes an event mesh manageable is not simply included with the broker

Pricing, plan by plan

GNAT Pro

On request

No published plan breakdown. See the GNAT Pro review.

Solace PubSub+

Free
  • Software Event Broker StandardFree
    • Free for production within capacity limits
    • Single node, capped connections and queues
    • No vendor support
  • Solace CloudOn request
    • Managed brokers in tiers from ENT-250 to ENT-100K
    • Foundation, Accelerate and Scale platform packages
    • Fixed subscription or annual consumption drawdown
  • Software Enterprise self-managedOn request
    • Deploy in your own Kubernetes, VMs or data centre
    • High availability and disaster recovery
    • Support with SLA
  • Hardware applianceOn request
    • Purpose-built appliance with FPGA message offload
    • Deterministic low latency
    • Sold with support contract

Which should you pick?

Choose GNAT Pro if

Nothing in the data separates GNAT Pro from Solace PubSub+ on the points above - pick on price and on how each one feels to use.

GNAT Pro review

Choose Solace PubSub+ if

  • You need multi-protocol broker.
  • You want to start without paying.
  • You work on Linux, Self-hosted, Web, Hardware appliance.
  • You also want dynamic message routing.
Solace PubSub+ review

Questions people ask

Is GNAT Pro or Solace PubSub+ better?
Neither clearly leads. GNAT Pro starts at On request and Solace PubSub+ at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, GNAT Pro or Solace PubSub+?
Solace PubSub+ has a free tier; the other does not. Paid plans start at On request for GNAT Pro and Free for Solace PubSub+.
Does GNAT Pro or Solace PubSub+ run on more platforms?
GNAT Pro runs on Web. Solace PubSub+ runs on Linux, Self-hosted, Web, Hardware appliance.
Can I use Solace PubSub+ for free?
Yes. Solace PubSub+ has a free tier, so you can try it without paying. GNAT Pro starts at On request.
What is GNAT Pro best used for?
GNAT Pro is most often used for building certified avionics software meeting do-178b/c standards, developing automotive embedded systems with iso-26262 compliance, integrating ada, c/c++, and rust components in single codebase, managing software supply chain vulnerabilities and sboms. Of those, building certified avionics software meeting do-178b/c standards and developing automotive embedded systems with iso-26262 compliance are not what Solace PubSub+ is typically brought in for.
What can GNAT Pro do that Solace PubSub+ cannot?
Solace PubSub+ covers Multi-protocol broker, Dynamic message routing, Hardware appliance, Event Portal.

Answered from the vendors’ own pages

GNAT Pro: How much does GNAT Pro cost?

GNAT Pro pricing is not published on the website. Customers must request a pricing quote by contacting AdaCore directly or speaking with a GNAT Pro expert.

Source
Solace PubSub+: Is there a free version of Solace?

Yes, the Standard edition of the software event broker is free for production within capacity limits, with no vendor support.

GNAT Pro: What is GNAT Pro licensing model?

GNAT Pro is sold on a per-user, per-year basis with no license locks. Customers can request pricing for their specific needs.

Source
Solace PubSub+: Does Solace publish prices?

No. Cloud, software and appliance are all quoted, based on broker tier from ENT-250 to ENT-100K and licensing model.

Solace PubSub+: Why buy an appliance in 2026?

Deterministic low latency with message processing offloaded to hardware, which matters in capital markets and little elsewhere.

Solace PubSub+: Can it replace Kafka?

Not for log retention and stream reprocessing. It is stronger at multi-protocol routing and guaranteed delivery, and the two are often bridged.

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