We've been building a templating engine API for PowerPoint. It lets you generate pptx by replacing {placeholders} in slides and populating tables and charts from JSON data.
My friend used to work at a web marketing/user testing firm, where they had to hand-edit monthly PowerPoint reports for each of their clients. He needed a developer-friendly way to automate that work, so he started building SlidePack (and I joined later).
If that's a problem you've experienced, please try this out and let me know what you think. If not, I'd love to hear what you think anyway.
Thank you!