Here is a small applet to display vector graphics from a file. Pressing i, j, k, m moves the point of view by a small amount. Pressing I, J, K, M moves the point of view by a larger amount. Pressing z doubles the scale, Z halves it. Pressing R reloads the file.
Mouse down starts a zoom-in.
Mouse up at once centers the view on the point. Mouse up somewhere else defines the second corner of the new view. Since the alpha3 version has frugal graphics, only rectangles, lines and strings are known. If anyone is working along those lines, I'd love to hear about it. If you use it, drop me a line.