John McLear JohnMcLear

## paxton-covert.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Paxton Fob converter</title>
<style>
table, th, td, div {
  border: 1px solid black;
}

## posa.mkdn

      
        
          
            
              
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                JohnMcLear
                / posa.mkdn
            
            
              Created
              December 5, 2012 16:42
                — forked from audreyt/posa.mkdn
            
              
                EtherCalc Chapter for POSA
              
          
        
      
        
  
      
    From SocialCalc to EtherCalc

Previously, in The Architecture of Open Source Applications, I described SocialCalc, an in-browser spreadsheet system that replaced the server-centric WikiCalc architecture. SocialCalc performs all of its computations in the browser; it uses the server only for loading and saving spreadsheets.
For the Socialtext team, performance was the primary goal behind SocialCalc's design in 2006. The key observation was this: Client-side computation in JavaScript, while an order of magnitude slower than server-side computation in Perl, was still much faster than the network latency incurred during AJAX roundtrips:
...diagram on SocialCalc's scalability model...
(Since that time, advances in JavaScript runtimes have mostly closed the gap; note that in the diagram.)
Toward the end of the AOSA chapter, we introduced simultaneous collaboration on spreadsheets, using a simple, chatroom-like architecture:
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>Paxton Fob converter</title>
	<style>
	table, th, td, div {
	border: 1px solid black;
	}