The genome of the poplar rust fungus Melampsora larici-populina has been sequenced almost 10 years ago by an international consortium in the frame of the Community Sequencing Program of the US DoE Joint Genome Institute. The detailed analysis of the genome content and gene annotation, along with comparison to the cereal rust fungus Puccinia graminis f.sp. tritici, has revealed the singular profile of rust fungal genomes. Similar to other obligate biotrophic fungi (e.g. powdery mildews), rust fungi exhibit a large genome size (>80Mb) and an important content in repeat elements (~45%). In contrast, they possess a large gene complement (>15,000 genes) marked by the presence of many expanded gene families specific to the Pucciniales order or the corresponding families (i.e. Melampsoraceae or Pucciniaceae). Since, more rust genomes have been sequenced, analyzed and published, confirming these general trends and opening great perspectives for comparative rust genomics. The genome of M. larici-populina has been instrumental to explore the genetic diversity of the fungus through re-sequencing of isolates sampled through the years in natural populations. Beside, gene expression during poplar leaf infection or throughout the life cycle has helped to build a comprehensive transcriptomic analysis of the rust fungus. More recently, a genetic map of the poplar rust fungus has been obtained from a self-cross of the reference genome isolate. All these data have led to the version 2 of the genome now anchored to 18 linkage groups, including a refined gene annotation available online on the MycoCosm website. We will provide here a complete update on the poplar rust genome and an overview of ongoing works to decipher the biology of this fascinating and devastating rust fungus.