> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Introduction to OSS > This article explores Open Source Softwares role in application development, its components, and Microsofts open source strategy. In this lesson, we’ll dive into Open Source Software (OSS) and its pivotal role in modern application development. You’ll learn how pre-built components accelerate delivery, and explore Microsoft’s comprehensive open source strategy on Azure and beyond. ## Understanding Software Composition When examined closely, up to 80% of a modern application’s architecture is assembled from existing components. These typically come from three main sources: | Component Source | Description | Examples | | ------------------------------ | ----------------------------------------------------- | --------------------------------------------- | | Internal (In-House) | Custom libraries, frameworks, and shared modules | Proprietary SDKs, company-specific toolchains | | Third-Party Commercial Vendors | Licensed middleware, frameworks, or complete software | Enterprise databases, paid analytics packages | | Open Source Community | Freely available libraries, tools, and frameworks | React, Kubernetes, TensorFlow | ![The image illustrates the software build process, highlighting that 80% of the architecture involves contributions from teams within the organization, third-party commercial entities, and the open-source community.](https://kodekloud.com/kk-media/image/upload/v1752868017/notes-assets/images/AZ-400-Designing-and-Implementing-Microsoft-DevOps-Solutions-Introduction-to-OSS/software-build-process-architecture-contributions.jpg) ## Ubiquity of Open Source in Development Open source components are now embedded in nearly every software project. Whether you’re building microservices or a large-scale web application, OSS libraries and frameworks are almost always part of the stack. ![The image illustrates the concept of the software build process, highlighting the ubiquity of open-source integration, with a person interacting with a computer screen displaying gears and icons.](https://kodekloud.com/kk-media/image/upload/v1752868018/notes-assets/images/AZ-400-Designing-and-Implementing-Microsoft-DevOps-Solutions-Introduction-to-OSS/software-build-process-open-source-integration.jpg) ## Defining Open Source Software Open source software is characterized by licenses that grant users the freedom to: * **Inspect**: View and understand the source code. * **Modify**: Adapt the code to fit unique requirements. * **Distribute**: Share original or altered versions with others. Transparency and collaboration are at the heart of OSS. These freedoms foster rapid innovation, peer review, and community-driven improvements. ## Microsoft’s Open Source Strategy Microsoft has embraced OSS across its entire ecosystem: * Enabling open source technologies on [Azure](https://azure.microsoft.com/) so you can choose your preferred tools and frameworks. * Contributing to and integrating projects like [.NET Core](https://dotnet.microsoft.com/) and [TypeScript](https://www.typescriptlang.org/). * Open sourcing flagship products such as [Visual Studio Code](https://code.visualstudio.com/). * Actively participating in external communities, making Microsoft one of the top OSS contributors globally. Be sure to review and comply with open source license obligations in your projects to avoid legal and security risks. ## Links and References * [Kubernetes Documentation](https://kubernetes.io/docs/) * [Docker Hub](https://hub.docker.com/) * [Terraform Registry](https://registry.terraform.io/) * [Azure Open Source](https://azure.microsoft.com/solutions/open-source/) * [Microsoft Open Source Guide](https://opensource.microsoft.com/)