LM Studio, built by Element Labs Inc., is a desktop and server runtime for running open-source LLMs — Qwen, Gemma, DeepSeek, gpt-oss, and others — entirely on local hardware, with no outbound API calls required. The GUI lets you download and chat with models in minutes; the headless CLI tool `llmster` extends the same runtime to Linux servers, cloud VMs, and CI pipelines with no interface overhead. An OpenAI-compatible API layer means existing code talking to OpenAI endpoints can be redirected to a local LM Studio server with minimal changes. The ceiling appears when you need the model to do something at scale: high-throughput production inference, fine-tuning, or multi-tenant serving — none of those are what this tool is built for.