Did R' Moshe de Leon write the Zohar

Question

Although "traditionally" ascribed to Rabbi Shimon bar Yochai zt"l, the Zohar has been beset with controversy about its authorship since it was discovered and published by R' Moshe de Leon. Notably there is a report cited below in the name of R' Moshe de Leon's widow's admitting that her late husband had authored the work himself.

a rich man of Avila, named Joseph, offered [de Leon's] widow, who had been left without means, a large sum of money for the original from which her husband had made the copy; and she then confessed that her husband himself was the author of the work. She had asked him several times, she said, why he had chosen to credit his own teachings to another, and he had always answered that doctrines put into the mouth of the miracle-working Simeon ben Yohai would be a rich source of profit. (Jewish Encyclopedia, see sources there)

What does contemporary Rabbinic and/or Academic scholarship have to say on the question of whether R de Leon himself composed the Zohar and to how much credibility is given to his widow's testimony?

Note this question does not ask if Rabbi Shimon Bar Yochai wrote it. That question was asked separately.

Answer 1

From Wikipedia:

R' Menachem Mendel Kasher in an article in the periodical Sinai refutes many of [Gershom] Scholem's points (used to argue that Zohar was authored by R. Moshe De Leon). He writes:

1. Many statements in the works of the Rishonim refer to Medrashim that we are not aware of. He writes that these are in fact references to the Zohar. This has also been pointed out by R' David Luria in his work "Kadmus Sefer Ha'Zohar".
2. The Zohar's major opponent Elijah Delmedigo refers to the Zohar as having existed for "only" 300 years. Even he agrees that it was extant before the time of R' Moses De Leon.
3. He brings a document from R' Yitchok M' Acco who was sent by the Ramban to investigate the Zohar. The document brings witnesses that attest to the existance of the manuscript.
4. It is impossible to accept that R' Moshe De Leon managed to forge a work of the scope of the Zohar (1700 pages) within a period of six years as Scholem claims.
5. A comparison between the Zohar and De Leon's other works show major stylistic differences. Although he made use of his manuscript of the Zohar, many ideas presented in his works contradict or ignore ideas mentioned in the Zohar. (Luria also points this out)
6. Many of the Midrashic works acheived their final redaction in the Geonic period. Some of the anachronistic terminology of the Zohar may date from that time.
7. Out of the thousands of words used in the Zohar Scholem finds two anachronistic terms and nine cases of ungrammatical usage of words. This proves that the majority of the Zohar was written within the accepted time frame and only a small amount was added later (in the Geonic period as mentioned).
8. Some hard to understand terms may be attributed to acronyms or codes. He finds corrolaries to such a practice in other ancient manuscripts.
9. The "borrowings" from medieval commentaries may be explained in a simple manner. It is not unheard of that a note written on the side of a text should on later copying be added into the main part of the text. The Talmud itself has Geonic additions from such a cause. Certainly this would apply to the Zohar to which there did not exist other manuscripts to compare it with.
10. He cites an ancient manuscript that refers to a book Sod Gadol that seems to in fact be the Zohar. Concerning the Zohars's lack of knowledge of the land of Israel, Scholem bases this on the many references to a city Kaputkia which he states was situated in Turkey not in Israel.

R' Reuvain Margolies (Peninim U' Margolies) states that in an ancient Israeli tombstone there is mentioned a village Kaputkia. In addition, the Zohar states that this village was sitiuated within a day's walk of Lod and Margolies's research corroborates this. This would imply that the author of the Zohar had precise knowledge of the geography of Israel.