vLLM is Apache 2.0: the patent grant is the key differentiator from MIT, and it terminates on patent litigation

You want to use vLLM in a commercial product and assume it's 'open source' like MIT. But Apache 2.0 has a patent grant that MIT lacks, and it terminates if you sue for patent infringement.

Apache 2.0 Section 3 grants a perpetual, worldwide, non-exclusive, royalty-free patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work. This is the key difference from MIT: if you sue vLLM contributors for patent infringement, your patent license terminates. This is a 'poison pill' patent clause.

If you use vLLM in a commercial product: (1) you can use, modify, and distribute vLLM freely, (2) you must include the Apache 2.0 license and NOTICE file, (3) you must state changes you made, (4) you cannot sue vLLM contributors for patent infringement without losing your patent license. If you need stronger patent protection, consider contributing to vLLM to get implicit patent rights.

Verified: vLLM's LICENSE file is the standard Apache 2.0 text (201 lines, 11.1 KB). The patent grant in Section 3 is the key clause. This is not a restriction on use — it's a restriction on patent litigation. Most commercial users are unaffected.