Written in Java, Jalatext is capable of opening very large (1 gig+) files almost instantly. Rather than churn madly trying to fit as much of the file as possible into RAM, it loads a small portion at a time, keeping performance swift. The user can adjust the size of the loaded segments, in accordance with their available RAM.

Once Jalatext is loaded, you can navigate by segment. If you tell it to load 10,000 lines at a time, each click of the appropriate control will move to the next/prior 10,000 lines. Or by scrolling within a segment. You can also rapidly go to the beginning/end of a file.

This points out one of the problems with Jalatext, namely, it's not easy to tell your relative position in a file.

Jalatext's status bar tells you the byte range being displayed, but not the line number, which is far more useful for many purposes. The scroll bar tells you the relative position of what you're seeing within the loaded segment, which is good, but there's little to provide a quick, intuitive, sense of your position within the file itself. If you know the area you're interested in is, say, line 234,500 out of 1 million lines, there is no "go to this line" function or command.

One thing that can mitigate this is the use of bookmarks.