BHairy
Commercial hair generating plugin for XSI. Generates hair for any version of XSI, including Foundation and Essentials. A one month free trial version is available.
Binder 1.1 for XSI 6+
Binder 1.1 for 5.11
Displacement alternative. Binds a base object in XSI to a high-poly sculpted object file. Animate and deform the base version in XSI. At render time the sculpted version is rendered.
XSIBase thread
zbump
Bump mapping shader. Just plug a texture or two into the inputs.
Note: As of XSI 6.01, zbump is included with Softimage XSI as the new bump node.
solid volume
Basic ray-marcher. Can use procedural input or volumetric datasets (See volume loader below). It can do limited non-solid ray-marching but you probably want to check out Binary Alchemy Volume shaders if you want something production-worthy for that.
solid volume basic example scenesolid volume non-solid example scene
XSIBase thread
volume loader
Loads 3D volumetric datasets (such as medical cross-sectional imaging data). This can then be rendered using Solid Volume ("Direct Volume Rendering").
Parallax
Steep Parallax shader. This can achieve displacement-like effects, except at the edges of an object. It uses a local ray-marching method around the ray-object intersection point rather than displacing geometry. It seems like it's usually slower than displacement.
Framestamp
Addon with output shader which will overlay text. Options include frame number, time, and render time; current date and time; XSI and MR versions; scene name; as well as arbitrary text input.
This uses the FreeType library and can display .ttf fonts.
Vector Displacement
This addon allows you to generate and apply displacement maps which displace in arbitrary directions, not just along the surface normal.