title: Create excel without interop and template with or without row and columnspan
body: <p>Which dll or library can be used to create the excelsheet which is not of a particular format such that a template can be used in this context. While the rows and columns may be merged. Number of columns are not fixed. </p>
  
  <p>For example: In the first row column 1 and 2 are merged while in the second row the 2 rows of second column are merged. Say first row is containing 5 columns while the second row is of 4 columns.</p>
  
  <p>Interop is not desired as the system running the program may not have Microsoft office installed with it.</p>
  
  <p>Any suggestions would be a great helping.</p>