Following the "create once - publish everywhere" mantra, I'll show how to build flexible content collections on selected topics from existing multimedia content using the ON:meedi:a ecosystem. In the talk, we will select a topic and build a collection from scratch starting with related social media posts, photos, videos, audio, documents and mixing it with own content. Along this adventure, we'll discuss the challenges that multimedia content poses and how they have been addressed in ON:meedi:a, as well applications in the area of learning content.