AXPs/SGRs: Magnetars or Quark-stars?
  The magnetar model and a solid quark star model for anomalous X-ray pulsars/soft gamma-ray repeaters (AXPs/SGRs) are discussed. Different manifestations of pulsar-like stars are speculated to be due to both their nature (e.g., mass and strain) and their nurture (ambience, and consequently the type of accretion) in the solid quark star scenario. Relevant arguments made by the author's group, including a debate on solid cold quark matter, are briefly summarized too. 
Renxin Xu (PKU)