The Microsoft-ization of Juniper Networks may be ending, as CEO Kevin Johnson is retiring, the company announced this afternoon.

Johnson will step down once a successor has been chosen, the company's press release states.

Johnson came to the company almost exactly five years ago, replacing founding CEO Scott Kriens. A Microsoft veteran, Johnson brought with him a strong marketing bent (a new look for an engineering-heavy company) -- and a lot of fellow Microsoft executives.  Among them is Bob Muglia, who's executive vice president of Juniper's Software Solutions Division and heads Juniper's software-defined networking (SDN) efforts.

Quite a few other executives left the company during his tenure.  Stefan Dyckerhoff, formerly executive vice president of the Platform Systems Division, left to join Sutter Hill Ventures. And longtime CTO Kireeti Kompella left for SDN startup Contrail Systems, which has subsequently been acquired by Juniper.

Under Johnson's leadership, Juniper stock climbed as high as $44.11 in early 2011, but it's since fallen to pre-2008 levels, closing at $21.34 today.