Speculative Decoding Frameworks

vLLM is a high-throughput inference engine designed for the efficient serving and execution of large language models. It functions as a production-ready distributed model server, providing standard API protocols for online serving while also supporting offline batch processing. The system is built to maximize token generation speed and memory efficiency, enabling both large-scale cloud deployments and local execution on personal hardware. The project distinguishes itself through advanced memory management and request scheduling techniques, most notably its use of non-contiguous key-value cache blocks to eliminate fragmentation and its ability to dynamically insert new sequences into batches as they arrive. It provides a hardware-agnostic abstraction layer that maps complex mathematical operations to diverse accelerators, including specialized GPUs and consumer-grade silicon like Apple hardware. This is further supported by custom kernel fusion and a flexible quantization framework that allows for the compression of neural networks to fit resource-constrained environments. Beyond its core runtime, the framework offers extensive support for custom

TensorRT-LLM is a platform and toolkit designed for compiling, optimizing, and serving transformer-based models on accelerated hardware. It functions as a framework that transforms machine learning models into efficient execution graphs, providing an engine to refine these models for specific hardware to maximize throughput and minimize latency during text generation. The project distinguishes itself through advanced execution strategies that manage the entire inference pipeline. It utilizes kernel-level fusion and static graph execution to optimize mathematical operations and computational flow, while implementing paged attention memory management to handle long sequence lengths without memory fragmentation. These capabilities are integrated with in-flight request batching and custom decoding logic, which allow for the direct implementation of sampling strategies within the execution pipeline to reduce data transfer overhead. The toolkit supports both online model serving for scalable, concurrent request handling and offline batch inference for high-volume, non-interactive processing. It provides comprehensive controls for managing attention memory and configuring decoding parameters, ensuring that hardware utilization remains efficient across diverse deployment environments.

Lorax is a GPU-accelerated inference server and multi-adapter engine designed for serving large language models. It functions as a high-throughput system capable of deploying models via Kubernetes and managing the dynamic swapping of Low-Rank Adaptation adapters per request. The server distinguishes itself through multi-adapter dynamic batching, which allows requests using different adapter weights to be processed in a single GPU forward pass. It employs just-in-time adapter loading and weighted adapter merging to maximize throughput and enable multi-tasking without sacrificing performance. The project provides a standardized interface for chat and completions that is compatible with common API protocols, supporting structured outputs via JSON schema enforcement. Its performance surface includes tensor parallelism, speculative decoding, paged attention, and model weight quantization to reduce latency and memory overhead. Infrastructure is managed through Helm charts for Kubernetes orchestration, with integrated telemetry exported via Prometheus and Open Telemetry.

llama.cpp is a high-performance C++ inference engine and runtime for executing large language models locally across various hardware architectures. It provides the core components for local model execution, including a dedicated model quantizer for compressing weights into the GGUF format and a system for generating text embeddings for semantic search. The project distinguishes itself through specialized memory and execution optimizations, such as block-wise weight quantization to reduce memory footprints and memory-mapped model loading. It supports structured text generation by using formal grammars to force model outputs to adhere to specific JSON schemas or patterns, and it implements speculative decoding to increase inference speed. Broad capabilities include hardware acceleration for GPUs, tools for converting models between different data formats, and utilities for measuring model quality via perplexity and divergence metrics. The engine can be wrapped in an HTTP server that provides an OpenAI-compatible API for integration with external tools.

Sglang is a high-performance inference engine and serving system designed for large language and multimodal models. It provides a programmable interface for orchestrating complex generation workflows, enabling developers to coordinate multi-turn dialogues, tool invocations, and reasoning chains through a domain-specific language. The platform is built to support production-scale deployments, offering an OpenAI-compatible API that allows for integration with existing application ecosystems. The system distinguishes itself through a disaggregated architecture that separates compute-intensive prompt processing from memory-intensive token generation across distinct hardware nodes. This approach, combined with a continuous batching engine and graph-captured kernel execution, maximizes hardware utilization and throughput. It also features dynamic adapter injection, allowing for the runtime switching of fine-tuning modules without requiring server restarts, and a hierarchical key-value cache management system that distributes state across GPU, host RAM, and external storage to support extended context windows. Beyond core serving, the project includes comprehensive capabilities for structured output generation, enforcing machine-readable formats like JSON schemas and regular expressions during the inference process. It supports advanced performance techniques such as speculative decoding, multi-token prediction, and sparse attention mechanisms. The engine also provides robust tools for traffic management, reliability enforcement, and distributed observability, ensuring consistent performance across heterogeneous hardware clusters.

llama-cpp-python provides a Python interface for the llama.cpp library, enabling the execution of large language models with hardware acceleration. It functions as a GGUF model loader and a structured text generator capable of running inference servers and multimodal runtimes for processing both text and image inputs. The project distinguishes itself through a local inference server that exposes model capabilities via an OpenAI-compatible web API. It supports advanced execution techniques including speculative decoding, weight quantization, and layer-based GPU offloading to manage memory across system RAM and VRAM. The library covers a broad range of AI capabilities, including text completion, embedding generation, and the enforcement of structured outputs via JSON schemas or formal grammars. It also provides infrastructure for tool use through external function calling and manages model extensions via LoRA adapter injection. Users can fetch model files directly from Hugging Face and maintain model state persistence for resuming generation.

Triton Inference Server is a high-performance server designed to deploy machine learning models from multiple frameworks across GPUs and CPUs. It functions as a hardware-accelerated inference engine and a gRPC inference gateway, providing a standardized communication layer for transmitting binary tensor data with low latency. The system acts as a multi-framework model orchestrator, allowing users to link multiple AI models into ensembles and scripts to create complex inference pipelines. It also serves as a model lifecycle manager, providing controls to load, unload, and monitor the performance of models in production environments. Throughput is optimized via dynamic batching, concurrent model execution, and stateful sequence batching. The server supports extensibility through custom inference backends implemented in C++ or Python and utilizes shared memory communication to reduce data copying overhead. Observability is provided through performance monitoring of hardware utilization, request throughput, and response latency.

LightLLM is a high-performance serving framework for deploying and executing large language models. It functions as a multi-GPU inference engine and server capable of handling dense architectures, mixture-of-experts designs, and multimodal models that process both text and images. The system is distinguished by its specialized support for Mixture-of-Experts models using expert parallelism and fused kernels. It implements structured text generation through deterministic state machines and pushdown automata to enforce precise output formats. To optimize throughput, the framework employs speculative decoding, paged key-value cache management, and a separated prefill and decode pipeline. The platform covers a broad range of operational capabilities, including tensor and data parallelism for scaling across hardware, multi-tier cache offloading for long context windows, and tool use integration for executing external functions. It also provides a standard interface for chat completions and dedicated tools for measuring request throughput and latency under real-world workloads. The project is implemented in Python and includes base classes for integrating custom model architectures.

lmdeploy is a high-performance inference engine and deployment framework for large language models and vision models. It functions as a multi-modal model server and compression toolkit designed to serve models with high throughput and low latency. The system enables the distribution of model services across multiple machines using request-based load balancing and tensor parallelism. It includes specialized tools for model quantization and compression to reduce the memory footprint of weights and caches. The framework covers broad capability areas including production deployment, distributed model orchestration, and multimodal model serving. It supports both online serving and offline batch inference processing.

MiniCPM is a collection of small language models designed for local, on-device deployment in resource-constrained environments. The project focuses on running dense Transformer models on consumer hardware, including GPUs, CPUs, and Apple Silicon, without requiring custom code forks. The project distinguishes itself through heavy optimization for edge hardware, utilizing quantized weight compression in GGUF and MLX formats to reduce memory overhead. It implements advanced inference techniques such as speculative sampling and radix-tree prefix caching to accelerate generation speed and throughput. Capability areas cover the full model lifecycle, including supervised fine-tuning and preference optimization via parameter-efficient LoRA adapters. The system supports structured tool calling for external agent integration and provides various serving options, including OpenAI-compatible APIs, REST endpoints, and a command-line interface. The implementation includes tools for converting model checkpoints between formats and distributing training workloads across multiple GPUs.

mistral.rs is an inference engine for large language models that runs locally and exposes models behind OpenAI and Anthropic-compatible APIs. It serves as a multi-model serving platform, capable of loading several models in a single server process with per-request routing and on-demand loading and unloading. The engine supports multimodal inference, processing text alongside images, video, audio, and speech inputs, and includes a quantized model deployment runtime that reduces memory use and speeds up inference on consumer hardware. The project distinguishes itself through an agentic tool execution framework that runs server-side tools like code execution, shell commands, and web search in an automated loop during model generation, with session state persistence. It provides an in-process inference engine that can be embedded directly into Rust or Python applications without a separate server process, and includes an in-situ quantization engine that converts model weights to lower precision at load time with per-layer tuning. The system supports structured output constraints, forcing model output to conform to JSON Schema or grammar specifications during decoding, and offers automatic architecture detection that identifies model type, quantization format, and chat template from a Hugging Face model ID. The platform includes capabilities for managing LoRA adapters, composing models as mixture-of-experts configurations, and running distributed inference across multiple GPUs or nodes using tensor parallelism and ring transport. It provides a built-in web chat interface, supports speculative decoding with a smaller assistant model, and offers benchmarking, logging, and Prometheus metrics for monitoring. The project can be run from a configuration file, with options for customizing build processes, tuning hardware settings automatically, and managing model caches.

Intel XPU LLM Acceleration Library is a toolkit designed to accelerate large language model inference and finetuning on Intel CPUs, GPUs, and NPUs. It provides a distributed inference engine for scaling models across multiple accelerators, a multimodal model runtime for vision and speech tasks, and a low-bit model quantization tool for converting weights into INT4, FP8, and GGUF formats. The project features a parameter-efficient finetuning framework that enables model adaptation using QLoRA and DPO on Intel hardware. It distinguishes itself by providing specialized optimizations for Intel XPU backends, including the ability to execute large Mixture-of-Experts models on consumer-grade hardware and perform NPU-specific model conversion. The library covers a broad range of capabilities, including inference optimization via speculative decoding and KV-cache compression, distributed workload distribution through tensor and pipeline parallelism, and the deployment of local retrieval-augmented generation pipelines. It also supports multimodal execution for visual question answering and audio transcription, alongside OpenAI-compatible API serving.

Transformers is a comprehensive library for machine learning that provides a unified interface for training, fine-tuning, and deploying transformer-based models. It supports a wide range of tasks, including text classification, language modeling, question answering, and sequence-to-sequence translation, while offering specialized architectures for both text and vision processing. The framework includes tools for managing the entire model lifecycle, from data preprocessing and tokenization to distributed training and inference. The library features extensive support for model optimization and performance, including techniques like quantization, speculative decoding, and paged memory management for key-value caches. It provides native integration for distributed training across multi-node clusters, as well as flexible APIs for serving models via compatible inference servers. Developers can also utilize built-in utilities for model patching, custom kernel execution, and automated documentation generation to streamline development workflows.

OpenVINO is an AI inference engine and model serving platform designed to execute optimized deep learning models across CPUs, GPUs, and NPUs through a unified API. It includes a model optimization toolkit for converting, quantizing, and compressing models from various frameworks, alongside a specialized generative AI runtime for large language models. The project distinguishes itself through a plugin-based hardware acceleration layer that maps neural network operations to vendor-specific drivers. It features advanced execution mechanisms such as continuous batching, speculative decoding, and a graph-based inference pipeline that orchestrates sequences of models and custom logic nodes. The platform covers a broad range of capabilities, including comprehensive model preparation via framework conversion and precision quantization, high-performance model serving through REST and gRPC endpoints, and deep observability through performance profiling and hardware affinity visualization. It also provides extensive deployment options ranging from bare metal server binaries to Kubernetes orchestration.

This project provides a Chinese large language model based on the LLaMA architecture. It is an instruction-tuned model optimized for natural language processing and multi-turn conversations in Chinese. The system includes a framework for parameter-efficient fine-tuning using low-rank adaptation and quantization to reduce memory requirements. It also implements retrieval augmented generation for local document question answering and supports long-context processing for sequences up to 64K tokens. The project covers a broad set of capabilities including supervised instruction tuning, reinforcement learning from human feedback for safety alignment, and multi-GPU distributed training. It also provides tools for model weight quantization, speculative decoding for inference acceleration, and a web-based interface for model interaction.

llm-compressor is a quantization toolkit and post-training library designed to reduce the memory footprint and size of large language models. It provides a framework for compressing models using weight and activation quantization to enable more efficient deployment. The project distinguishes itself through a distributed quantization framework that utilizes data-parallel processing and disk-based weight offloading to handle massive model checkpoints that exceed available system memory. It includes specialized compressors for diverse architectures, including Mixture-of-Experts, Vision-Language, and Audio-Language models. The toolkit covers a broad range of optimization capabilities, including calibration-based and data-free quantization, checkpoint format conversion, and the reduction of precision for attention mechanisms and key-value caches. It manages these processes through structured compression recipes and orchestration pipelines to standardize model preparation and optimization.

Burn is a deep learning framework designed for building, training, and deploying neural networks using a modular architecture. As a machine learning library built in Rust, it provides a backend-agnostic computational engine that enables the execution of models across diverse hardware, including central processors, graphics processors, and web runtimes. The framework distinguishes itself through a highly portable design that allows developers to maintain a single workflow for both training and inference across heterogeneous environments. It incorporates advanced optimization techniques such as just-in-time kernel fusion, asynchronous execution, and static graph compilation to maximize computational efficiency and hardware throughput. The library also functions as a comprehensive model quantization toolkit, offering tools to convert weights and activations into lower-bit representations. These capabilities facilitate the deployment of neural networks on resource-constrained edge devices by reducing memory footprints and accelerating inference tasks without requiring manual code changes for different hardware targets.

ColossalAI is a distributed deep learning framework designed for training and deploying massive artificial intelligence models across clusters of hardware accelerators. It functions as a parallel computing engine that partitions model workloads and data across multiple processors to maximize memory efficiency and throughput. The platform distinguishes itself through a comprehensive suite of parallelization strategies, including multi-dimensional tensor parallelism and pipeline-based model parallelism, which segment neural network layers and stages across devices. To support large-scale generative models in production, it provides a distributed inference runtime that utilizes dynamic request batching and optimized communication primitives to manage high volumes of concurrent traffic and minimize latency. The framework incorporates a large model optimization suite that enables the execution of complex models on limited hardware. This includes heterogeneous memory offloading, which moves parameters between GPU memory and system storage, and kernel-level computation optimizations that replace standard operations to reduce memory overhead. These capabilities facilitate both the training of massive models and the deployment of generative applications in production environments.

BitNet is a quantized inference engine designed to execute highly compressed language models by performing arithmetic on low-precision, bit-level weight data. It functions as a model optimization toolkit and a high-performance kernel library, enabling the execution of large language models on consumer hardware by reducing memory footprints and increasing processing speeds. The project distinguishes itself through hardware-specific kernel optimizations that leverage native processor instructions to accelerate matrix multiplication. By utilizing packed integer arithmetic and memory-aligned weight permutation, the engine improves cache locality and computational density. These capabilities are specifically tuned to accelerate autoregressive decoding, minimizing latency during the sequential token generation process to support real-time text generation requirements. The toolkit includes a comprehensive suite for hardware-accelerated neural computation, allowing users to benchmark inference kernels and measure generation latency against baseline implementations. These tools ensure that the inference pipeline maintains high throughput and efficiency when processing compressed models on supported graphics hardware.

KoboldCPP is a local large language model inference engine and GGUF model runner designed to execute quantized models on personal hardware. It functions as a multimodal AI server and API gateway, providing OpenAI-compatible endpoints that allow third-party clients to interact with locally hosted models. The project distinguishes itself as an AI storytelling backend, featuring dedicated tools for long-form narrative management through persistent memory, world lore tracking, and character state management. It further extends its capabilities as a multimodal server capable of processing text, images, and audio using vision projectors and speech synthesis. The system includes broad support for hardware acceleration via GPU-layer offloading and multi-GPU tensor splitting to handle large models. It incorporates advanced output control through grammar constraints and phrase banning, as well as grounded retrieval capabilities that connect models to local documents and web search. The core runtime is implemented in C++ for high-performance memory management and hardware-level optimization.