Addgene's lentiviral vectors are produced with the 2nd generation psPAX2-based packaging system developed by the Trono lab. The particles should not necessarily be considered "2nd generation lentiviruses" - as the generation is largely defined by the transfer plasmid, and the 2nd generation system (psPAX2) can be used to package 2nd generation transfer plasmids and 3rd generation transfer plasmids.
The enveloping plasmid used is pMD2.G and the vectors are therefore "VSV-G pseudotyped." The pseudotyping determines the tropism of the vector, and VSV-G pseudotypes are considered "pantropic" vectors (vectors capable of transducing a wide variety of cell types).
For complete details on how our lentiviral vectors are produced, visit our Viral Production page and the pages linked therein.