Courses repeat every 28 days or 21 days (patients with hematological malignancies only) in the absence of disease progression or unacceptable toxicity. In both groups, cohorts of 3-6 patients receive escalating doses of vorinostat until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. The dose level just below MTD would be declared the recommended phase II dose (RPTD). Up to 10 patients are treated at the RPTD. After completion of study treatment, patients are followed at 4 weeks.