Open-source alternatives to KurrentDB

Zeebe is a cloud-native workflow engine and distributed state machine designed for business process orchestration using BPMN and DMN standards. It operates as a high-performance gRPC workflow runtime that executes complex business processes through a partitioned event-streaming architecture. The system also functions as an orchestrator for large language model agents, coordinating AI reasoning and tool use within deterministic business processes. The engine is distinguished by its peer-to-peer broker networking and a consensus-based data replication model that ensures high availability and fa

Mercure is an HTTP-based message broker and real-time pub/sub server that routes asynchronous data updates to authorized subscribers. It functions as a centralized hub that receives data via standard HTTP requests and broadcasts it to web clients using the Server-Sent Events protocol. The project distinguishes itself by replacing WebSockets with a unidirectional HTTP connection, leveraging HTTP/2 and HTTP/3 for multiplexed, low-latency delivery. It implements a secure access control layer using JSON Web Tokens and JSON Web Signatures to validate the identity of publishers and subscribers, and

The etcd-operator is a custom resource controller designed to automate the deployment, scaling, backup, and recovery of distributed key-value storage clusters on container orchestration platforms. By extending container orchestration APIs with custom resource definitions, the system manages multi-node database instances through declarative configuration files and a continuous controller reconciliation loop that drives cluster provisioning, scaling, and maintenance. The operator provides automated cluster member recovery, detecting unresponsive nodes and executing membership replacements to pr

The AWS Cloud Development Kit is an infrastructure-as-code framework that enables developers to define and provision cloud resources using familiar programming languages. By utilizing construct-based synthesis, it translates high-level, object-oriented code into declarative templates, allowing for the automated management of complex cloud environments through a centralized, code-driven control plane. The framework distinguishes itself through its ability to model infrastructure as a dependency-aware resource graph, ensuring that components are provisioned and updated in the correct order. It

This project is an open-source, self-hosted platform designed for enterprise-grade data collection, survey building, and automated operational workflows. It provides a comprehensive environment for organizations to maintain full data sovereignty while managing interactive questionnaires, online exams, and complex information-gathering projects within their own private infrastructure. The platform distinguishes itself through a focus on high-concurrency, scalable deployment and granular organizational control. It features a dynamic drag-and-drop builder that supports logic-based branching and

Zend Framework is a comprehensive set of decoupled components for building modular, event-driven web applications. It implements an MVC architecture to separate business logic from the user interface and provides a structured request-handling system through a sequential middleware pipeline. The project features a factory-driven dependency injection container to automate object instantiation and manage class lifecycles. It also includes a comprehensive security suite for verifying user identities and restricting resource access using access control lists and role-based access control adapters.

Openblocks is a low-code platform for building custom internal tools. It provides a visual interface where users can assemble applications by dragging and dropping pre-built components onto a canvas, connecting them to databases and APIs without writing code. The platform distinguishes itself through its architecture for embedding and reuse. Entire application pages can be rendered as native React components inside other applications, replacing traditional iframe-based embedding. Custom components and queries can be bundled into reusable modules for use across multiple applications, and an au

Scanopy is a self-hosted infrastructure inventory and network discovery tool. It identifies hosts, services, and workloads across subnets to build a live model of network infrastructure, maintaining a searchable catalog of assets. The system features an interactive network topology visualizer that generates physical, logical, and application dependency diagrams. It maps the nesting chain from physical hardware and hypervisors down to virtual machines and containers, utilizing SNMP for hardware metadata and container APIs for workload discovery. The platform supports distributed network scann

Kimai is an open-source time tracking system that records employee working hours, manages absences, and generates professional invoices from recorded timesheets and expenses. It organizes all time records through a mandatory three-level hierarchy of customer, project, and activity, and supports project budget monitoring with configurable time and money limits. The application is extensible through a plugin system that allows adding custom features, invoice templates, reporting views, and dashboard widgets without modifying core files. It provides a RESTful JSON API for programmatic read and w

Passbolt is an open-source, self-hosted password manager designed for teams. It provides a centralized, encrypted vault where organizations can store, share, and manage credentials securely. The server exposes a JSON REST API that authenticates requests using either GPGAuth or JWT tokens, and all secrets are protected with OpenPGP end-to-end encryption, ensuring the server never has access to plaintext passwords. The platform distinguishes itself through a comprehensive role-based access control system that governs resource sharing and administrative actions. Teams can organize users into gro

This project is a Kubernetes deployment guide and infrastructure provisioner designed for hobbyist and home lab environments. It provides a framework for setting up multi-node clusters across various cloud providers and physical or virtual nodes, acting as a self-hosted cluster orchestrator. The project focuses on security hardening and infrastructure stability through specific implementation guides. This includes a framework for network security that covers host firewalls and encrypted network overlays, as well as detailed instructions for configuring ingress routing to manage external publi

Hi.Events is an open-source event management platform designed for organizing events, managing ticket tiers, and processing payments. It functions as a multi-tenant ticketing system, allowing multiple independent organizations to operate on a single instance with strict data isolation and role-based access control. The platform specializes in white-label event ticketing, featuring custom branding for event pages and embeddable checkout widgets for external websites. It includes a real-time sales analytics dashboard to monitor revenue, growth, and attendee check-in performance. The system cov

This project is a self-hosted enterprise wiki platform designed for teams to create, organize, and share documentation. It functions as a centralized knowledge management system that enables collaborative authoring through markdown syntax, allowing users to structure information within isolated departmental spaces and private team workspaces. The platform distinguishes itself through a focus on operational simplicity and administrative control. It is distributed as a single, self-contained executable binary, which streamlines deployment by eliminating complex runtime dependencies. To support

This platform is a comprehensive, white-label software suite designed for launching and managing on-demand food delivery services. It provides a unified ecosystem that connects customers, restaurant staff, and delivery riders through integrated mobile and web interfaces, supported by a centralized backend infrastructure that synchronizes data and business logic across all user roles. The system distinguishes itself through its focus on self-hosted deployment, granting operators full control over their data, backups, and server environments. It supports multi-vertical business models, allowing

ZenML is an orchestration platform designed for building, deploying, and monitoring reproducible machine learning pipelines and agentic workflows. It provides a unified framework that manages the entire lifecycle of machine learning assets, from data processing and model training to the deployment of persistent inference services. By decoupling pipeline logic from underlying compute and storage, the platform enables teams to transition workflows seamlessly from local development environments to production-grade cloud infrastructure. The platform distinguishes itself through a service-oriented

Inngest is a durable execution framework and event-driven automation engine designed to orchestrate background workflows. It enables developers to build resilient, stateful processes by memoizing function steps, ensuring that long-running tasks can automatically resume from the last successful operation after failures, timeouts, or infrastructure restarts. The platform distinguishes itself through its event-driven architecture, which uses a schema-validated bus to trigger functions and coordinate complex, multi-step logic. It employs an onion-model middleware approach for cross-cutting concer

Rallly is a group scheduling tool and collaborative event planner designed to coordinate meeting dates and collect participant availability. It functions as a multi-tenant meeting coordinator that allows users to propose date options via polls, visualize overlapping free time in a grid, and finalize meeting arrangements across different time zones. The project is built as a self-hosted scheduling application that can be deployed on private infrastructure using a containerized stack. This deployment model enables full data ownership and includes capabilities for corporate identity branding, al

ZenML is an extensible machine learning orchestration framework designed to manage the end-to-end lifecycle of data pipelines and AI agent workflows. It functions as a durable orchestrator that executes machine learning tasks as directed acyclic graphs, ensuring that every step is containerized for consistent performance across local, cloud, and hybrid infrastructure. By decoupling pipeline code from underlying compute and storage backends, the platform allows developers to define infrastructure-agnostic stacks that remain portable across diverse environments. The project distinguishes itself

This project is a Kubernetes operator designed for deploying and managing production PostgreSQL database clusters using declarative configurations. It functions as a controller that synchronizes the actual state of database clusters with a desired state, providing a system for high availability orchestration, automated backup and recovery, and containerized database administration. The operator distinguishes itself through a comprehensive data protection suite that supports point-in-time recovery, multi-mode backups to cloud object storage, and cluster cloning. It ensures continuous availabil

This project provides containerized images for deploying a self-managed content collaboration and file sharing server. It enables the creation of private cloud storage and self-hosted file synchronization environments, allowing users to maintain data ownership and control over their infrastructure. The deployment model utilizes Docker images to simplify installation, scaling, and version updates. It distinguishes itself through a database-agnostic storage approach, supporting integration with PostgreSQL, MySQL, MariaDB, or SQLite, and employs volume mapping to ensure data persistence across c

Deepagents is an LLM agent orchestration platform and stateful application server designed for deploying and managing AI agents built with computational graphs. It provides a containerized runtime environment that handles agent execution, state persistence, and the versioning of AI assistants. The platform distinguishes itself through deep integration with the Model Context Protocol, allowing agents to function as servers that expose tools and capabilities to external clients. It features a sophisticated observability suite for capturing execution traces, performing LLM-based evaluations agai

Cube is a time-series analytics platform and event data store designed for real-time performance monitoring. It functions as a metrics engine that ingests timestamped event streams and persists raw logs to enable the computation of statistical summaries, quantiles, and histograms. The system distinguishes itself through a reactive processing model that automatically invalidates metric caches when new events arrive, ensuring query results remain current. It supports both real-time event streaming via persistent connections and the calculation of post hoc statistics from stored event sets. The

Commanded is an Elixir framework designed for building event-sourced applications that utilize domain-driven design. It provides a structured environment for implementing command-query responsibility segregation, allowing developers to separate write-side command processing from read-side data projection. By treating state changes as an immutable sequence of events, the framework ensures a reliable audit trail and facilitates system recovery. The project distinguishes itself through its support for distributed process orchestration and event-driven middleware pipelines. It enables the managem

Akka.NET is an actor model framework used for building concurrent and distributed applications. It functions as a distributed computing platform and state manager that enables isolated actors to communicate via asynchronous message passing, ensuring thread-safe state management without manual locks. The project is distinguished by its decentralized coordination capabilities, including a distributed state manager that uses sharding and dynamic rebalancing to maintain high availability. It incorporates an event sourcing engine that persists state as a sequence of events in an append-only log an

o2oa is an open-source Java enterprise office automation platform designed to manage corporate workflows, organizational hierarchies, and collaborative office tasks. It functions as a low-code business application platform and a corporate information portal, providing a visual development environment for building custom enterprise applications. The platform is distinguished by its integrated enterprise workflow engine, which allows for the design and automation of business processes using customizable routing conditions and event-driven scripts. It further differentiates itself as a multi-dat

Libredesk is an omnichannel support management system designed to unify live chat and email communications into a single dashboard. It provides a comprehensive environment for managing customer interactions, agent roles, and team assignments to organize support workloads. The project distinguishes itself through AI customer support automation, which includes generating automated responses and refining message tones. It also supports the development and integration of custom chat widgets using WebSockets and JavaScript APIs. The system covers a broad set of capabilities, including customer re

ag-ui is an agent-frontend interoperability layer and communication protocol designed to connect AI agent backends with web and mobile user interfaces. It provides a standardized event-driven framework for exchanging messages, session state, and tool calls, utilizing a generative UI framework to render dynamic interface components and structured content triggered by an agent. The project distinguishes itself through an SSE-based event streamer that delivers real-time incremental model responses and reasoning telemetry. It enables bi-directional state synchronization and allows remote agents t