SFP+ Transceivers (Small Form-Factor Pluggable) are the upgraded form of the former SFP transceivers (mini GBIC), with higher data rate and new industrial standards. It's smaller than any of the currently shipping form factors and offers the greatest density per line card. SFP+ offers customers both immediate benefits and long-term advantages in supporting evolving data center needs. The SFP+ specification was first published on May 9, 2006, and version 4.1 published on July 6, 2009. It is a international industry format supported by many network component vendors. 

SFP+ is definitely an innovative, next-generation transceiver module. Initially, it is geared to support speeds of 10 Gbps for next-generation Gigabit Ethernet applications and 8.5Gbps Fiber Channel systems. What is more, SFP plus is with lower power consumption for less than 1W which is even economical. These transceivers are with managed digital optical monitoring and superior high temperature performance. 

Several industrial acknowledged standards for SFP plus has been released for 10Gpbs networks, including 10Gbase-SR, which define the SFP plus transceiver dealing with OM3 10G multimode fiber at 30 to 300 meters range, 10Gbase-LR which define the SFP plus transceiver dealing with single mode fiber at 10km range, 10Gbase-LRM which define the FDDI multimode fiber around 220 meters range. 

Compare With XENPAK or XFP Modules 
Compared to earlier XENPAK or XFP modules, SFP+ module is with more compact size compared with the previous 10G transceivers X2 and Xenpak, leave more circuitry to become implemented around the host board instead of within the module. 
The benefits of SFP+ modules: 
SFP+ Includes a More Compact Form Factor Package Than X2 And XFP. 
It Can Interact with The Same Data Rate Of XFP, X2 And XENPAK Directly. 
The price of SFP Is gloomier Than XFP, X2 And XENPAK. 

SFP+  Transceiver is interchangeable with SFP transceiver and can be used in exactly the same cages as SFP transceiver. For 10G applications, SFP+  transceiver has a smaller footprint minimizing power consumption than XFP transceiver. The electrical interface towards the host board for SFP transceiver and SFP+  transceiver is identical serial. 

Many companies, for example Cisco, Finisar, and Sumitomo, have released SFP+ transceivers. SFP+  ensure the 10Gbps data transmission and also the most densely installation capability as well as the lowest cost, currently it's well known as the best option for the 10Gbps fiber optic transceivers. Among them, Cisco SFP+  transceiver may be the mainstream market. Cisco 10Gbase SFP+  transceivers are used for high speed 10Gigabit Ethernet, linking the gear to fiber optic networks. Cisco SFP+  products include active SFP+  cables and SFP+  transceivers. There is also copper transceiver offered by Cisco.