Lucene Solr is an open source technology and community that has proved its worth in heavy hitting applications inside platform companies like LinkedIn and Zappos.
Last week GT Solar ( SOLR), a global provider of polysilicon production technology, crystalline ingot growth systems and related photovoltaic manufacturing services for the solar industry, announced that it had acquired privately-held Crystal Systems.
Another ETF with exposure to solar is the Market Vectors Solar Energy ETF ( KWT) which counts GT Solar ( SOLR) as its largest holding at a 10.46% weighting, followed closely by First Solar at 10.09%.