Yes, those terms match your pictures. My vote is for beech, but it’s still a guess. It grows in the region (Jura Mountains), is a hardwood and has a similar grain pattern and bark.

I don’t think it is ash - the bark does not look right. Having a cross section showing the face grain and end grain is often helpful to identify wood from a picture.

Just because source is available does not mean it’s an open source license. It’s still proprietary, free to use for non-commercial use only.

If you want something that’s really open source, consider Joplin (AGPL-3.0, https://github.com/laurent22/joplin/) or CherryTree (GPL3, https://github.com/giuspen/cherrytree).