Application design
The application is written in Python, using wxPython for the GUI part, and pickle for saving and loading the data.
The data structure is a simple Python dictionary with the tab titles as keys and the text field contents as values. Using pickle eliminates the need to convert this before saving and converting it back after loading.
Basic GUI components are a tab bar, a multi-line text field and an event loop capturing special key combinations. The first two are realized using a notebook interface where each page of the notebook is a panel containing a text field.
recent changes
On moving to Python 3, wxPython had to be exchanged for PyQt, which meant a slightly different look. I tried to keep the feel the same. The notebook is now a tabwidget, and built in behaviour might be a bit different.