Self-indexing (and traditional indexing) algorithms - Implementations and advice to share?

As part of a research project I'm currently looking for open-source implementations of self-indexing algorithms, i.e. a compressed form of the traditional inverted index yielding nice characteristics such as faster lookup and/or less consumed s开发者_开发知识库pace.

Do you know of any open-source implementations of self-indexing algorithms? Do you have other interesting takes on indexing algorithms or data structures to share?

All languages and license variants are welcome.

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Here is a nice introductory presentation on self-indexing (PDF).

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Look at this page: http://pizzachili.dcc.uchile.cl/, it offers a lot of the existing implementations for those indexes.

Some background and a description of the page can be found in this paper: http://dl.acm.org/citation.cfm?id=1455268