Ha0.999[14] is a recent (1995) compression program by Harri Hirvola designed for general files, either text or images. It has two methods, which are described in the documentation thus:
1-ASC: Default method using sliding window dictionary followed by arithmetic coder. Offers quite good compression on wide variety of file types.We tried both methods on both the ASCII and the binary heights. Compressing the binary data was, as usual, about 10% better. Ha-2 was somewhat smaller than ha-1, and sometimes faster, sometimes slower. Ha-2 on the binary data gave 3.2 bpp. However, ha is about twice as slow as gzip.2-HSC: Compression method based on finite context model and arithmetic coder. Quite slow for binary data, but offers very good compression especially for longer text files.