This script will convert .obml and .obml16 files that were saved using Opera Mini into HTML files which can be opened in any web browser.
The program requires Python 3. There are no external dependencies besides that, so you can just run:
./obml-parser *.obml
Why is text misaligned?
Note that because OBML files are the output of Opera's HTML rendering engine, many elements are pixel-positioned according to the original device's screen size and font metrics. Because many J2ME devices had custom fonts (optimized for low-res screens), it's possible that your computer will show the same text as too-tall or too-wide, and lines may overlap.
It may be possible to work around this by editing font_sizes and line_height at the top of the script.
This is nothing specific to the converter – your saved pages would look similarly misaligned if they were copied into a different J2ME device and opened with the real Opera Mini.
What's up with hyperlinks?
OBML does not have <a href=...>, i.e. you cannot actually have text that is also a link. Instead the engine outputs text and links as two separate layers – first it places the actual text at position (X,Y), then overlays it with "link" rectangles at position (X,Y,W,H).
So when you're viewing the page on a different device, links will appear to be misaligned – but it's actually the text which will shift around (due to different font metrics) while the links remain in their original position.
(The converter could do some guessing, but if you have a chunk of text in which only some words are linked, then it is very difficult to programmatically determine which specific words were originally covered by the link rectangles.)
Other interesting things
OBML does not have styled widgets the way HTML would. The style is actually pre-rendered, and those pretty 3D effects are made out of pixel-positioned lines and rectangles. Even button gradients are pre-rendered and drawn as a series of 1-pixel thin lines.