vLLM

VLLM is an open-source large language model serving engine built around PagedAttention, which manages the KV cache the way an operating system manages virtual memory, and continuous batching, which keeps GPU utilization high under variable load. The project targets production deployments where throughput per GPU matters, positioning itself against ease-of-use tools like Ollama and llama.cpp and as a self-hosted alternative to managed inference services such as Together AI. vLLM is backed by compute resources from AWS, Google Cloud, NVIDIA, and AMD, and is maintained by an active open-source community.

Open Source Alternative to: Stars Last commit Repository age Version License Self-hosted Repository vLLM is a serving engine for large language models, built for teams and developers who need to run LLMs at scale without burning through GPU budgets. It's designed around two core problems: throughput and memory. Most inference setups waste GPU memory and process requests inefficiently. vLLM addresses both. The engine's standout technique is PagedAttention , which manages the KV cache the way an operating system manages virtual memory. This dramatically reduces memory waste and allows more requests to run concurrently on the same hardware. Paired with continuous batching , it keeps GPU utilization high even under variable load, rather than waiting to fill a fixed batch before processing. Key capabilities include: For teams building on top of LLMs, vLLM fits naturally into LLM application frameworks https://openalternative.co/categories/ai-machine-learning/ai-development-platforms/llm-application-frameworks and works alongside routing layers like LiteLLM https://openalternative.co/litellm or an LLM gateway https://openalternative.co/llm-gateway for multi-provider setups. It's a common self-hosted alternative to managed inference services like Together AI https://openalternative.co/alternatives/together-ai . Compared to tools like Ollama https://openalternative.co/ollama or llama.cpp https://openalternative.co/llama-cpp , which prioritize ease of use on consumer hardware, vLLM targets production deployments where throughput per GPU matters. It's backed by compute resources from AWS, Google Cloud, NVIDIA, AMD, and others, and maintained by an active open-source community with support channels for both newcomers and teams running complex deployments. Every Sunday we deconstruct one proprietary app and pick the best open source alternatives worth switching to. Compare with