Introducing: web-based viewer of Dark Colony game files (supported: SPR, BTS, FIN, MAP). It renders the files directly in your browser window! (Note: currently works only in Chrome 49 and later).
Rendering engine is based on explanations by Dreamerman - author of original SPR2BMP.
Written in new object-oriented JavaScript ES6, which is why it cannot work in older browsers. Eventually, this kind of platform could be used for web-based remake of Dark Colony.
Thanks to Maranta for operating this DC fan site and pointing me to the right forum to post in (don't understand Polish very well..)