A side-by-side comparison of release history, capabilities, licensing and model sizes.
| Attribute |
 Jurassic
|
Muse |
|---|---|---|
| Developer | AI21 | Meta Superintelligence Labs |
| Current generation | – | Muse Spark 1.1 |
| Initial release | 2021-08-11 | 2026-04-08 |
| Instruct tuned | Yes | Yes |
| Coding | Yes | Yes |
| Finetuning | Yes | No |
| Open source | No | No |
| License | NA | Proprietary |
| Model sizes | 7.5B, 17B, 178B, Unknown | Undisclosed |
| Links |
Developed by AI21, a startup founded by luminaries from Stanford and Mobileye, Jurassic was one of the first LLMs to challenge GPT-3. While it includes some support for code, Jurassic is more focused on reading and writing use cases, perhaps linked to AI21's development of other tools such as Wordtune. Jurassic also introduced the MRKL system for interfacing with external, non-neural modules.
Muse is Meta's new proprietary multimodal reasoning and agent family. Muse Spark 1.1 powers Meta AI and succeeds Llama as Meta's actively promoted assistant model line.
Meta introduced Muse Spark in April 2026 as the first model from Meta Superintelligence Labs' ground-up Muse series. It is a natively multimodal reasoning model with tool use, visual reasoning, and multi-agent orchestration. Muse Spark 1.1, announced in July 2026, adds planning and action capabilities across research, productivity, and connected applications. It powers Meta AI and is available through Meta's products, with API access offered in private preview rather than as open weights.
