It varies more than it should. The developer is pretty well standardized to Defender 54-D, although others may creep in depending on the paper and pure whim. The papers vary quite a bit, but it's mostly Ilford Multigrade RC (coldtone). Lately I have been working with Adox RC papers, and I rather like them. Forma is usually my choice for a warmtone paper, with some confusion when it comes to a warmtone developer.