The low-level protocol the whole system runs on. It is not a club of precept specialists.
The Vinaya school sits oddly in this server list: it is not a branch you can join.
Every monastic in East Asian Buddhism, whether Chan (Zen), Tiantai or Pure Land, is ordained under the same Dharmaguptaka Vinaya (Four-Part Vinaya). That system is what this school left behind. In the language of the game: it is not a server, it is the low-level protocol every server shares.
The Four-Part Vinaya opens onto the Mahāyāna: the Dharmaguptaka Vinaya belongs to a mainstream school (the Dharmaguptakas), and Daoxuan reinterpreted it through Mahāyāna doctrine so that a Mahāyāna community could accept it. It is the key move in Nanshan Vinaya.
The precept-essence as a mental factor: Daoxuan held that the essence of the precepts is a wholesome seed perfumed into the ālaya consciousness. Note that this takes the Yogācāra framework over directly. Ordination writes a seed to the database. It does not issue a certificate. The move wires precept-keeping into the mechanism of perfuming.
Teaching for transformation and teaching for regulation: the first is the general instruction given to beings (sutras and treatises), the second the concrete rules of the community (vinaya). The distinction exists so that the vinaya does not get read as moral preaching.
The basis of monastic ordination in East Asia. 250 precepts for monks, 348 for nuns.
Daoxuan's most important work, and the operating manual for how East Asian monastic communities actually run.
The precepts explained one by one.
The rules of karman, the community's formal deliberation and procedure. One of the earliest texts of procedural rules in Buddhism, and very interesting read as a document about how meetings should work.
The authoritative Song-dynasty commentary on the three Nanshan works.
Li Shutong took up Nanshan Vinaya after his ordination and was the central figure in its modern revival. His writings are the best way into the subject today.
Novice precepts, full precepts and bodhisattva precepts received in sequence on three platforms. A form of ordination particular to East Asia.
Every half month the community gathers to recite the precepts and disclose faults. One of the oldest institutions in Buddhism, and it is still running.
Three months of the rainy season spent in one place in concentrated practice, ending with an invitation to the other monastics to point out your faults (pavāraṇā).
The formal procedure by which the community handles its business, with strict requirements on quorum, sequence and assent. Read as organisational design, it is a set of meeting rules from two and a half thousand years ago.
A point worth getting right: every school in East Asian Buddhism uses the same body of vinaya. Monastics are not ordained into "the Vinaya school's precepts", and the school was never a group of unusually strict people. What it did was organise the system, interpret it and keep it running.
On what the vinaya is for: in Daoxuan's framework its function is closer to giving a community that lives together a predictable operating environment than to restriction and prohibition. The karman procedures make that especially plain.
A third point of record: after the Song most vinaya monasteries were converted into Chan monasteries, and the separate vinaya monastery system has been gone for a long time. The school disappeared as an entity while the institution kept running.
For an ordinary reader the most valuable part of the Vinaya school is probably the karman system rather than the precepts themselves. A set of rules for collective deliberation designed two and a half thousand years ago and still in use.
If you read Chinese, Master Hongyi's writings on the vinaya are the right place to start. He was the one person in the modern period who made Nanshan Vinaya live again, and he wrote in a way that works for lay readers. None of it has been translated, so in English the Nanshan material has to be reached through scholarship.