Facilitates comparative analysis of ChIP-chip data across experiments and across different microarray platforms. Starr provides functions for data import, quality assessment, data visualization and exploration. It includes high-level analysis tools such as the alignment of ChIP signals along annotated features, correlation analysis of ChIP signals with complementary genomic data, peak-finding and comparative display of multiple clusters of binding profiles. It uses standard Bioconductor classes for maximum compatibility with other software. Moreover, Starr automatically updates microarray probe annotation files by a highly efficient remapping of microarray probe sequences to an arbitrary genome. Finally, Starr enables systematic assessment of binding behaviour for groups of genes that are alingned along arbitrary genomic features.