Abstract:
We present several results on hadronic D meson decays. We report on results from the scan of the energy region from 3970 MeV to 4260 MeV, which was used to determine an optimal energy to carry out the D_s physics program of CLEO-c. Improved measurements of inclusive and exclusive D and D_s branching fractions are presented. We also show results on Dalitz analyses of D^+-->pi^+pi^-pi^+ using CLEO-c data and D^0--> K^+K^-pi^0 using CLEO III data.

Abstract:
Recent results include the measurement of B->D(*)pi+pi-pi-pi0 decays, with rates of ~1.8% observation of a significant omega pi^- substructure that appears to result from the decay of the rho' resonance, whose mass and width we determine as 1418 MeV and 382 MeV, respectively. Using B to charmonium decays we find that the neutral B fraction in Y(4S) decays is nearly half, that the CP asymmetries in J/\psi K^(-/+) and psi' K^(-/+) are small, and we also report on the first observation of B->eta_c K.

Abstract:
Using an inclusive method, BR(b -> D\bar{D}X) has been measured in hadronic Z^0 decays with the OPAL detector at LEP. The impact parameter significance of tracks opposite tagged b-jets is used to differentiate b -> D\bar{D}X decays from other decays. Using this result, the average number of charm and anti-charm quarks produced per beauty quark decay, n_c, is determined.

Abstract:
Based on the CLEO II and II.5 data sets CLEO has observed several new rare and hadronic B decays and also updated the b->s+gamma measurement.

Abstract:
I present highlights of recent CLEO results on the hadronic decay modes of the B meson. Topics covered include two body rare B decays modes, a new measurement of $(B^0 \to D^0 K^+) / (B^0 \to D^0 \pi^+)$, an in depth study of the decay $B^0 \to D^* \rho$, as well as a preliminary search for charge asymmetry in the decay $B^0 \to K^* \pi$.

Abstract:
A selfconsistent treatment of nonperturbative effects in inclusive nonleptonic and semileptonic decays of beauty and charm hadrons is presented. It is illustrated by calculating semileptonic branching ratios, lifetime ratios, radiative decay rates and the lepton spectra in semileptonic decays.

Abstract:
Exclusive decays of B and D mesons are discussed with the focus on the theoretical problem how to calculate the relevant hadronic matrix elements of weak operators in the framework of QCD sum rules. The three lectures are devoted to 1. leptonic decays and decay constants 2. semileptonic decays and form factors 3. nonleptonic decays and nonfactorizable amplitudes. I shall introduce some of the basic concepts, describe various calculational techniques, and illustrate the numerical results. The latter are compared with lattice and quark model predictions and, where possible, with experimental data. Applications include the determination of V_{ub} from B -> \pi \bar{l} \nu_l and B -> \rho \bar{l} \nu_l, and an estimate of the phenomenological coefficient a_2 for B -> J/\psi K.

Abstract:
The parton model, a zero-order approximation in many treatments, is shown to be a ``semiclassical" model whose results for certain averages also hold (correspondence principle) in quantum mechanics. Algebraic techniques developed for the M\"ossbauer effect exploit simple features of commutators to obtain sum rules showing the validity of the parton model for $b \rightarrow c$ semileptonic decays in the classical limit, $\hbar \rightarrow 0$, where all commutators vanish, and in general, even when binding effects are included, for the lowest moments of the lepton energy spectrum at fixed 3-momentum transfer. Interference between the $u \bar u$ and $d \bar d$ components of the $\rho^o$ and $\omega$ wave functions can be used as clues to contributions from small weak amplitudes and CP violation in decays to final states including these vector mesons.